diff --git a/hasql-th.cabal b/hasql-th.cabal
--- a/hasql-th.cabal
+++ b/hasql-th.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name: hasql-th
-version: 0.4.0.23
+version: 0.4.1
 category: Hasql, Database, PostgreSQL, Template Haskell
 synopsis: Template Haskell utilities for Hasql
 description:
@@ -21,10 +21,10 @@
 
 source-repository head
   type: git
-  location: git://github.com/nikita-volkov/hasql-th.git
+  location: https://github.com/nikita-volkov/hasql-th
 
 library
-  hs-source-dirs: library
+  hs-source-dirs: src/library
   default-extensions:
     ApplicativeDo
     Arrows
@@ -83,7 +83,7 @@
     containers >=0.6 && <0.8,
     contravariant >=1.5.2 && <2,
     foldl >=1.4.5 && <2,
-    hasql >=1.4 && <1.10,
+    hasql >=1.10 && <1.11,
     postgresql-syntax >=0.4.1 && <0.5,
     template-haskell >=2.8 && <3,
     template-haskell-compat-v0208 >=0.1.9 && <2,
diff --git a/library/Hasql/TH.hs b/library/Hasql/TH.hs
deleted file mode 100644
--- a/library/Hasql/TH.hs
+++ /dev/null
@@ -1,279 +0,0 @@
-module Hasql.TH
-  ( -- * Statements
-
-    -- |
-    --  Quasiquoters in this category produce Hasql `Statement`s,
-    --  checking the correctness of SQL at compile-time.
-    --
-    --  To extract the information about parameters and results of the statement,
-    --  the quoter requires you to explicitly specify the Postgres types for placeholders and results.
-    --
-    --  Here's an example of how to use it:
-    --
-    --  >selectUserDetails :: Statement Int32 (Maybe (Text, Text, Maybe Text))
-    --  >selectUserDetails =
-    --  >  [maybeStatement|
-    --  >    select name :: text, email :: text, phone :: text?
-    --  >    from "user"
-    --  >    where id = $1 :: int4
-    --  >    |]
-    --
-    --  As you can see, it completely eliminates the need to mess with codecs.
-    --  The quasiquoters directly produce `Statement`,
-    --  which you can then `Data.Profunctor.dimap` over using its `Data.Profunctor.Profunctor` instance to get to your domain types.
-    --
-    --  == Type mappings
-    --
-    --  === Primitives
-    --
-    --  Following is a list of supported Postgres types and their according types on the Haskell end.
-    --
-    --  - @bool@ - `Bool`
-    --  - @int2@ - `Int16`
-    --  - @int4@ - `Int32`
-    --  - @int8@ - `Int64`
-    --  - @float4@ - `Float`
-    --  - @float8@ - `Double`
-    --  - @numeric@ - `Data.Scientific.Scientific`
-    --  - @char@ - `Char`
-    --  - @text@ - `Data.Text.Text`
-    --  - @bytea@ - `Data.ByteString.ByteString`
-    --  - @date@ - `Data.Time.Day`
-    --  - @timestamp@ - `Data.Time.LocalTime`
-    --  - @timestamptz@ - `Data.Time.UTCTime`
-    --  - @time@ - `Data.Time.TimeOfDay`
-    --  - @timetz@ - @(`Data.Time.TimeOfDay`, `Data.Time.TimeZone`)@
-    --  - @interval@ - `Data.Time.DiffTime`
-    --  - @uuid@ - `Data.UUID.UUID`
-    --  - @inet@ - @(`Network.IP.Addr.NetAddr` `Network.IP.Addr.IP`)@
-    --  - @json@ - `Data.Aeson.Value`
-    --  - @jsonb@ - `Data.Aeson.Value`
-    --
-    --  === Arrays
-    --
-    --  Array mappings are also supported.
-    --  They are specified according to Postgres syntax: by appending one or more @[]@ to the primitive type,
-    --  depending on how many dimensions the array has.
-    --  On the Haskell end array is mapped to generic `Data.Vector.Generic.Vector`,
-    --  allowing you to choose which particular vector implementation to map to.
-    --
-    --  === Nulls
-    --
-    --  As you might have noticed in the example,
-    --  we introduce one change to the Postgres syntax in the way
-    --  the typesignatures are parsed:
-    --  we interpret question-marks in them as specification of nullability.
-    --  Here's more examples of that:
-    --
-    --  >>> :t [singletonStatement| select a :: int4? |]
-    --  ...
-    --    :: Statement () (Maybe Int32)
-    --
-    --  You can use it to specify the nullability of array elements:
-    --
-    --  >>> :t [singletonStatement| select a :: int4?[] |]
-    --  ...
-    --    :: Data.Vector.Generic.Base.Vector v (Maybe Int32) =>
-    --       Statement () (v (Maybe Int32))
-    --
-    --  And of arrays themselves:
-    --
-    --  >>> :t [singletonStatement| select a :: int4?[]? |]
-    --  ...
-    --    :: Data.Vector.Generic.Base.Vector v (Maybe Int32) =>
-    --       Statement () (Maybe (v (Maybe Int32)))
-
-    -- ** Row-parsing statements
-    singletonStatement,
-    maybeStatement,
-    vectorStatement,
-    foldStatement,
-
-    -- ** Row-ignoring statements
-    resultlessStatement,
-    rowsAffectedStatement,
-
-    -- * SQL ByteStrings
-
-    -- |
-    --  ByteString-producing quasiquoters.
-    --
-    --  For now they perform no compile-time checking.
-    uncheckedSql,
-    uncheckedSqlFile,
-  )
-where
-
-import qualified Data.Text as Text
-import qualified Data.Text.Encoding as Text
-import qualified Hasql.TH.Construction.Exp as Exp
-import qualified Hasql.TH.Extraction.Exp as ExpExtraction
-import Hasql.TH.Prelude hiding (exp)
-import Language.Haskell.TH.Quote
-import Language.Haskell.TH.Syntax
-import qualified PostgresqlSyntax.Ast as Ast
-import qualified PostgresqlSyntax.Parsing as Parsing
-
--- * Helpers
-
-exp :: (String -> Q Exp) -> QuasiQuoter
-exp =
-  let _unsupported _ = fail "Unsupported"
-   in \_exp -> QuasiQuoter _exp _unsupported _unsupported _unsupported
-
-expParser :: (Text -> Either Text Exp) -> QuasiQuoter
-expParser _parser =
-  exp $ \_inputString -> either (fail . Text.unpack) return $ _parser $ fromString _inputString
-
-expPreparableStmtAstParser :: (Ast.PreparableStmt -> Either Text Exp) -> QuasiQuoter
-expPreparableStmtAstParser _parser =
-  expParser $ \_input -> do
-    _ast <- first fromString $ Parsing.run (Parsing.atEnd Parsing.preparableStmt) _input
-    _parser _ast
-
--- * Statement
-
--- |
--- @
--- :: `Statement` params row
--- @
---
--- Statement producing exactly one result row.
---
--- Will cause the running session to fail with the
--- `Hasql.Session.UnexpectedAmountOfRows` error if it's any other.
---
--- === __Examples__
---
--- >>> :t [singletonStatement|select 1 :: int2|]
--- ... :: Statement () Int16
---
--- >>> :{
---   :t [singletonStatement|
---        insert into "user" (email, name)
---        values ($1 :: text, $2 :: text)
---        returning id :: int4
---        |]
--- :}
--- ...
--- ... :: Statement (Text, Text) Int32
---
--- Incorrect SQL:
---
--- >>> :t [singletonStatement|elect 1|]
--- ...
---   |
--- 1 | elect 1
---   |      ^
--- ...
-singletonStatement :: QuasiQuoter
-singletonStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement Exp.singleRowResultDecoder)
-
--- |
--- @
--- :: `Statement` params (Maybe row)
--- @
---
--- Statement producing one row or none.
---
--- === __Examples__
---
--- >>> :t [maybeStatement|select 1 :: int2|]
--- ... :: Statement () (Maybe Int16)
-maybeStatement :: QuasiQuoter
-maybeStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement Exp.rowMaybeResultDecoder)
-
--- |
--- @
--- :: `Statement` params (`Vector` row)
--- @
---
--- Statement producing a vector of rows.
---
--- === __Examples__
---
--- >>> :t [vectorStatement|select 1 :: int2|]
--- ... :: Statement () (Vector Int16)
-vectorStatement :: QuasiQuoter
-vectorStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement Exp.rowVectorResultDecoder)
-
--- |
--- @
--- :: `Fold` row folding -> `Statement` params folding
--- @
---
--- Function from `Fold` over rows to a statement producing the result of folding.
--- Use this when you need to aggregate rows customly.
---
--- === __Examples__
---
--- >>> :t [foldStatement|select 1 :: int2|]
--- ... :: Fold Int16 b -> Statement () b
-foldStatement :: QuasiQuoter
-foldStatement = expPreparableStmtAstParser ExpExtraction.foldStatement
-
--- |
--- @
--- :: `Statement` params ()
--- @
---
--- Statement producing no results.
---
--- === __Examples__
---
--- >>> :t [resultlessStatement|insert into "user" (name, email) values ($1 :: text, $2 :: text)|]
--- ...
--- ... :: Statement (Text, Text) ()
-resultlessStatement :: QuasiQuoter
-resultlessStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement (const Exp.noResultResultDecoder))
-
--- |
--- @
--- :: `Statement` params Int64
--- @
---
--- Statement counting the rows it affects.
---
--- === __Examples__
---
--- >>> :t [rowsAffectedStatement|delete from "user" where password is null|]
--- ...
--- ... :: Statement () Int64
-rowsAffectedStatement :: QuasiQuoter
-rowsAffectedStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement (const Exp.rowsAffectedResultDecoder))
-
--- * SQL ByteStrings
-
--- |
--- Quoter of a multiline Unicode SQL string,
--- which gets converted into a format ready to be used for declaration of statements.
-uncheckedSql :: QuasiQuoter
-uncheckedSql = exp $ return . Exp.byteString . Text.encodeUtf8 . fromString
-
--- |
--- Read an SQL-file, containing multiple statements,
--- and produce an expression of type `ByteString`.
---
--- Allows to store plain SQL in external files and read it at compile time.
---
--- E.g.,
---
--- >migration1 :: Hasql.Session.Session ()
--- >migration1 = Hasql.Session.sql [uncheckedSqlFile|migrations/1.sql|]
-uncheckedSqlFile :: QuasiQuoter
-uncheckedSqlFile = quoteFile uncheckedSql
-
--- * Tests
-
--- $
--- >>> :t [maybeStatement| select (password = $2 :: bytea) :: bool, id :: int4 from "user" where "email" = $1 :: text |]
--- ...
--- ... Statement (Text, ByteString) (Maybe (Bool, Int32))
---
--- >>> :t [maybeStatement| select id :: int4 from application where pub_key = $1 :: uuid and sec_key_pt1 = $2 :: int8 and sec_key_pt2 = $3 :: int8 |]
--- ...
--- ... Statement (UUID, Int64, Int64) (Maybe Int32)
---
--- >>> :t [singletonStatement| select 1 :: int4 from a left join b on b.id = a.id |]
--- ...
--- ... Statement () Int32
diff --git a/library/Hasql/TH/Construction/Exp.hs b/library/Hasql/TH/Construction/Exp.hs
deleted file mode 100644
--- a/library/Hasql/TH/Construction/Exp.hs
+++ /dev/null
@@ -1,201 +0,0 @@
--- |
--- Expression construction.
-module Hasql.TH.Construction.Exp where
-
-import qualified Data.ByteString as ByteString
-import qualified Data.ByteString.Unsafe as ByteString
-import qualified Data.Vector.Generic as Vector
-import qualified Hasql.Decoders as Decoders
-import qualified Hasql.Encoders as Encoders
-import qualified Hasql.Statement as Statement
-import Hasql.TH.Prelude hiding (sequence_)
-import qualified Hasql.TH.Prelude as Prelude
-import Language.Haskell.TH.Syntax
-import qualified TemplateHaskell.Compat.V0208 as Compat
-
--- * Helpers
-
-appList :: Exp -> [Exp] -> Exp
-appList = foldl' AppE
-
-byteString :: ByteString -> Exp
-byteString x =
-  appList
-    (VarE 'unsafeDupablePerformIO)
-    [ appList
-        (VarE 'ByteString.unsafePackAddressLen)
-        [ LitE (IntegerL (fromIntegral (ByteString.length x))),
-          LitE (StringPrimL (ByteString.unpack x))
-        ]
-    ]
-
-integral :: (Integral a) => a -> Exp
-integral x = LitE (IntegerL (fromIntegral x))
-
-list :: (a -> Exp) -> [a] -> Exp
-list renderer x = ListE (map renderer x)
-
-string :: String -> Exp
-string x = LitE (StringL x)
-
-char :: Char -> Exp
-char x = LitE (CharL x)
-
-sequence_ :: [Exp] -> Exp
-sequence_ = foldl' andThen pureUnit
-
-pureUnit :: Exp
-pureUnit = AppE (VarE 'Prelude.pure) (TupE [])
-
-andThen :: Exp -> Exp -> Exp
-andThen exp1 exp2 = AppE (AppE (VarE '(*>)) exp1) exp2
-
-tuple :: Int -> Exp
-tuple = ConE . tupleDataName
-
-splitTupleAt :: Int -> Int -> Exp
-splitTupleAt arity position =
-  let nameByIndex index = Name (OccName ('_' : show index)) NameS
-      names = enumFromTo 0 (pred arity) & map nameByIndex
-      pats = names & map VarP
-      pat = TupP pats
-      exps = names & map VarE
-      body = splitAt position exps & \(a, b) -> Compat.tupE [Compat.tupE a, Compat.tupE b]
-   in LamE [pat] body
-
--- |
--- Given a list of divisible functor expressions,
--- constructs an expression, which composes them together into
--- a single divisible functor, parameterized by a tuple of according arity.
-contrazip :: [Exp] -> Exp
-contrazip = \case
-  _head : [] -> _head
-  _head : _tail -> appList (VarE 'divide) [splitTupleAt (succ (length _tail)) 1, _head, contrazip _tail]
-  [] ->
-    SigE
-      (VarE 'conquer)
-      ( let _fName = mkName "f"
-            _fVar = VarT _fName
-         in ForallT
-              [Compat.specifiedPlainTV _fName]
-              [AppT (ConT ''Divisible) (VarT _fName)]
-              (AppT (VarT _fName) (TupleT 0))
-      )
-
--- |
--- Given a list of applicative functor expressions,
--- constructs an expression, which composes them together into
--- a single applicative functor, parameterized by a tuple of according arity.
---
--- >>> $(return (cozip [])) :: Maybe ()
--- Just ()
---
--- >>> $(return (cozip (fmap (AppE (ConE 'Just) . LitE . IntegerL) [1,2,3]))) :: Maybe (Int, Int, Int)
--- Just (1,2,3)
-cozip :: [Exp] -> Exp
-cozip = \case
-  _head : [] -> _head
-  _head : _tail ->
-    let _length = length _tail + 1
-     in foldl'
-          (\a b -> AppE (AppE (VarE '(<*>)) a) b)
-          (AppE (AppE (VarE 'fmap) (tuple _length)) _head)
-          _tail
-  [] -> AppE (VarE 'pure) (TupE [])
-
--- |
--- Lambda expression, which destructures 'Fold'.
-foldLam :: (Exp -> Exp -> Exp -> Exp) -> Exp
-foldLam _body =
-  let _stepVarName = mkName "progress"
-      _initVarName = mkName "start"
-      _extractVarName = mkName "finish"
-   in LamE
-        [ Compat.conP
-            'Fold
-            [ VarP _stepVarName,
-              VarP _initVarName,
-              VarP _extractVarName
-            ]
-        ]
-        (_body (VarE _stepVarName) (VarE _initVarName) (VarE _extractVarName))
-
--- * Statement
-
-statement :: Exp -> Exp -> Exp -> Exp
-statement _sql _encoder _decoder =
-  appList (ConE 'Statement.Statement) [_sql, _encoder, _decoder, ConE 'True]
-
-noResultResultDecoder :: Exp
-noResultResultDecoder = VarE 'Decoders.noResult
-
-rowsAffectedResultDecoder :: Exp
-rowsAffectedResultDecoder = VarE 'Decoders.rowsAffected
-
-singleRowResultDecoder :: Exp -> Exp
-singleRowResultDecoder = 'Decoders.singleRow & VarE & AppE
-
-rowMaybeResultDecoder :: Exp -> Exp
-rowMaybeResultDecoder = AppE (VarE 'Decoders.rowMaybe)
-
-rowVectorResultDecoder :: Exp -> Exp
-rowVectorResultDecoder = AppE (VarE 'Decoders.rowVector)
-
-foldStatement :: Exp -> Exp -> Exp -> Exp
-foldStatement _sql _encoder _rowDecoder =
-  foldLam (\_step _init _extract -> statement _sql _encoder (foldResultDecoder _step _init _extract _rowDecoder))
-
-foldResultDecoder :: Exp -> Exp -> Exp -> Exp -> Exp
-foldResultDecoder _step _init _extract _rowDecoder =
-  appList (VarE 'fmap) [_extract, appList (VarE 'Decoders.foldlRows) [_step, _init, _rowDecoder]]
-
-unidimensionalParamEncoder :: Bool -> Exp -> Exp
-unidimensionalParamEncoder nullable =
-  applyParamToEncoder . applyNullabilityToEncoder nullable
-
-multidimensionalParamEncoder :: Bool -> Int -> Bool -> Exp -> Exp
-multidimensionalParamEncoder nullable dimensionality arrayNull =
-  applyParamToEncoder
-    . applyNullabilityToEncoder arrayNull
-    . AppE (VarE 'Encoders.array)
-    . applyArrayDimensionalityToEncoder dimensionality
-    . applyNullabilityToEncoder nullable
-
-applyParamToEncoder :: Exp -> Exp
-applyParamToEncoder = AppE (VarE 'Encoders.param)
-
-applyNullabilityToEncoder :: Bool -> Exp -> Exp
-applyNullabilityToEncoder nullable = AppE (VarE (if nullable then 'Encoders.nullable else 'Encoders.nonNullable))
-
-applyArrayDimensionalityToEncoder :: Int -> Exp -> Exp
-applyArrayDimensionalityToEncoder levels =
-  if levels > 0
-    then AppE (AppE (VarE 'Encoders.dimension) (VarE 'Vector.foldl')) . applyArrayDimensionalityToEncoder (pred levels)
-    else AppE (VarE 'Encoders.element)
-
-rowDecoder :: [Exp] -> Exp
-rowDecoder = cozip
-
-unidimensionalColumnDecoder :: Bool -> Exp -> Exp
-unidimensionalColumnDecoder nullable =
-  applyColumnToDecoder . applyNullabilityToDecoder nullable
-
-multidimensionalColumnDecoder :: Bool -> Int -> Bool -> Exp -> Exp
-multidimensionalColumnDecoder nullable dimensionality arrayNull =
-  applyColumnToDecoder
-    . applyNullabilityToDecoder arrayNull
-    . AppE (VarE 'Decoders.array)
-    . applyArrayDimensionalityToDecoder dimensionality
-    . applyNullabilityToDecoder nullable
-
-applyColumnToDecoder :: Exp -> Exp
-applyColumnToDecoder = AppE (VarE 'Decoders.column)
-
-applyNullabilityToDecoder :: Bool -> Exp -> Exp
-applyNullabilityToDecoder nullable = AppE (VarE (if nullable then 'Decoders.nullable else 'Decoders.nonNullable))
-
-applyArrayDimensionalityToDecoder :: Int -> Exp -> Exp
-applyArrayDimensionalityToDecoder levels =
-  if levels > 0
-    then AppE (AppE (VarE 'Decoders.dimension) (VarE 'Vector.replicateM)) . applyArrayDimensionalityToDecoder (pred levels)
-    else AppE (VarE 'Decoders.element)
diff --git a/library/Hasql/TH/Extraction/ChildExprList.hs b/library/Hasql/TH/Extraction/ChildExprList.hs
deleted file mode 100644
--- a/library/Hasql/TH/Extraction/ChildExprList.hs
+++ /dev/null
@@ -1,611 +0,0 @@
-{-# OPTIONS_GHC -Wno-missing-signatures #-}
-
-module Hasql.TH.Extraction.ChildExprList where
-
-import Hasql.TH.Prelude hiding (bit, fromList, sortBy)
-import PostgresqlSyntax.Ast
-
--- * Types
-
-data ChildExpr = AChildExpr AExpr | BChildExpr BExpr | CChildExpr CExpr
-  deriving (Show, Eq, Ord)
-
--- |
--- Dives one level of recursion.
-childExpr = \case
-  AChildExpr a -> aChildExpr a
-  BChildExpr a -> bChildExpr a
-  CChildExpr a -> cChildExpr a
-
-aChildExpr = \case
-  CExprAExpr a -> cChildExpr a
-  TypecastAExpr a b -> aExpr a <> typename b
-  CollateAExpr a b -> aExpr a <> anyName b
-  AtTimeZoneAExpr a b -> aExpr a <> aExpr b
-  PlusAExpr a -> aExpr a
-  MinusAExpr a -> aExpr a
-  SymbolicBinOpAExpr a b c -> aExpr a <> symbolicExprBinOp b <> aExpr c
-  PrefixQualOpAExpr a b -> qualOp a <> aExpr b
-  SuffixQualOpAExpr a b -> aExpr a <> qualOp b
-  AndAExpr a b -> aExpr a <> aExpr b
-  OrAExpr a b -> aExpr a <> aExpr b
-  NotAExpr a -> aExpr a
-  VerbalExprBinOpAExpr a b c d e -> aExpr a <> verbalExprBinOp c <> aExpr d <> foldMap aExpr e
-  ReversableOpAExpr a b c -> aExpr a <> aExprReversableOp c
-  IsnullAExpr a -> aExpr a
-  NotnullAExpr a -> aExpr a
-  OverlapsAExpr a b -> row a <> row b
-  SubqueryAExpr a b c d -> aExpr a <> subqueryOp b <> subType c <> either selectWithParens aExpr d
-  UniqueAExpr a -> selectWithParens a
-  DefaultAExpr -> []
-
-bChildExpr = \case
-  CExprBExpr a -> cChildExpr a
-  TypecastBExpr a b -> bExpr a <> typename b
-  PlusBExpr a -> bExpr a
-  MinusBExpr a -> bExpr a
-  SymbolicBinOpBExpr a b c -> bExpr a <> symbolicExprBinOp b <> bExpr c
-  QualOpBExpr a b -> qualOp a <> bExpr b
-  IsOpBExpr a b c -> bExpr a <> bExprIsOp c
-
-cChildExpr = \case
-  ColumnrefCExpr a -> columnref a
-  AexprConstCExpr a -> aexprConst a
-  ParamCExpr a b -> foldMap indirection b
-  InParensCExpr a b -> aExpr a <> foldMap indirection b
-  CaseCExpr a -> caseExpr a
-  FuncCExpr a -> funcExpr a
-  SelectWithParensCExpr a b -> selectWithParens a <> foldMap indirection b
-  ExistsCExpr a -> selectWithParens a
-  ArrayCExpr a -> either selectWithParens arrayExpr a
-  ExplicitRowCExpr a -> explicitRow a
-  ImplicitRowCExpr a -> implicitRow a
-  GroupingCExpr a -> exprList a
-
-preparableStmt = \case
-  SelectPreparableStmt a -> selectStmt a
-  InsertPreparableStmt a -> insertStmt a
-  UpdatePreparableStmt a -> updateStmt a
-  DeletePreparableStmt a -> deleteStmt a
-  CallPreparableStmt a -> callStmt a
-
--- * Call
-
-callStmt (CallStmt a) = funcApplication a
-
--- * Insert
-
-insertStmt (InsertStmt a b c d e) =
-  foldMap withClause a
-    <> insertTarget b
-    <> insertRest c
-    <> foldMap onConflict d
-    <> foldMap returningClause e
-
-insertTarget (InsertTarget a b) = qualifiedName a <> colId b
-
-insertRest = \case
-  SelectInsertRest a b c -> foldMap insertColumnList a <> foldMap overrideKind b <> selectStmt c
-  DefaultValuesInsertRest -> []
-
-overrideKind _ = []
-
-insertColumnList = foldMap insertColumnItem
-
-insertColumnItem (InsertColumnItem a b) = colId a <> foldMap indirection b
-
-onConflict (OnConflict a b) = foldMap confExpr a <> onConflictDo b
-
-onConflictDo = \case
-  UpdateOnConflictDo b c -> setClauseList b <> foldMap whereClause c
-  NothingOnConflictDo -> []
-
-confExpr = \case
-  WhereConfExpr a b -> indexParams a <> foldMap whereClause b
-  ConstraintConfExpr a -> name a
-
-returningClause = targetList
-
--- * Update
-
-updateStmt (UpdateStmt a b c d e f) =
-  foldMap withClause a
-    <> relationExprOptAlias b
-    <> setClauseList c
-    <> foldMap fromClause d
-    <> foldMap whereOrCurrentClause e
-    <> foldMap returningClause f
-
-setClauseList = foldMap setClause
-
-setClause = \case
-  TargetSetClause a b -> setTarget a <> aExpr b
-  TargetListSetClause a b -> setTargetList a <> aExpr b
-
-setTarget (SetTarget a b) = colId a <> foldMap indirection b
-
-setTargetList = foldMap setTarget
-
--- * Delete
-
-deleteStmt (DeleteStmt a b c d e) =
-  foldMap withClause a
-    <> relationExprOptAlias b
-    <> foldMap usingClause c
-    <> foldMap whereOrCurrentClause d
-    <> foldMap returningClause e
-
-usingClause = fromList
-
--- * Select
-
-selectStmt = \case
-  Left a -> selectNoParens a
-  Right a -> selectWithParens a
-
-selectNoParens (SelectNoParens a b c d e) =
-  foldMap withClause a
-    <> selectClause b
-    <> foldMap sortClause c
-    <> foldMap selectLimit d
-    <> foldMap forLockingClause e
-
-selectWithParens = \case
-  NoParensSelectWithParens a -> selectNoParens a
-  WithParensSelectWithParens a -> selectWithParens a
-
-withClause (WithClause _ a) = foldMap commonTableExpr a
-
-commonTableExpr (CommonTableExpr a b c d) = preparableStmt d
-
-selectLimit = \case
-  LimitOffsetSelectLimit a b -> limitClause a <> offsetClause b
-  OffsetLimitSelectLimit a b -> offsetClause a <> limitClause b
-  LimitSelectLimit a -> limitClause a
-  OffsetSelectLimit a -> offsetClause a
-
-limitClause = \case
-  LimitLimitClause a b -> selectLimitValue a <> exprList b
-  FetchOnlyLimitClause a b c -> foldMap selectFetchFirstValue b
-
-offsetClause = \case
-  ExprOffsetClause a -> aExpr a
-  FetchFirstOffsetClause a b -> selectFetchFirstValue a
-
-selectFetchFirstValue = \case
-  ExprSelectFetchFirstValue a -> cExpr a
-  NumSelectFetchFirstValue _ _ -> []
-
-selectLimitValue = \case
-  ExprSelectLimitValue a -> aExpr a
-  AllSelectLimitValue -> []
-
-forLockingClause = \case
-  ItemsForLockingClause a -> foldMap forLockingItem a
-  ReadOnlyForLockingClause -> []
-
-forLockingItem (ForLockingItem a b c) =
-  foldMap (foldMap qualifiedName) b
-
-selectClause = either simpleSelect selectWithParens
-
-simpleSelect = \case
-  NormalSimpleSelect a b c d e f g ->
-    foldMap targeting a
-      <> foldMap intoClause b
-      <> foldMap fromClause c
-      <> foldMap whereClause d
-      <> foldMap groupClause e
-      <> foldMap havingClause f
-      <> foldMap windowClause g
-  ValuesSimpleSelect a -> valuesClause a
-  TableSimpleSelect a -> relationExpr a
-  BinSimpleSelect _ a _ b -> selectClause a <> selectClause b
-
-targeting = \case
-  NormalTargeting a -> foldMap targetEl a
-  AllTargeting a -> foldMap (foldMap targetEl) a
-  DistinctTargeting a b -> foldMap exprList a <> foldMap targetEl b
-
-targetList = foldMap targetEl
-
-targetEl = \case
-  AliasedExprTargetEl a _ -> aExpr a
-  ImplicitlyAliasedExprTargetEl a _ -> aExpr a
-  ExprTargetEl a -> aExpr a
-  AsteriskTargetEl -> []
-
-intoClause = optTempTableName
-
-fromClause = fromList
-
-fromList = foldMap tableRef
-
-whereClause = aExpr
-
-whereOrCurrentClause = \case
-  ExprWhereOrCurrentClause a -> aExpr a
-  CursorWhereOrCurrentClause a -> cursorName a
-
-groupClause = foldMap groupByItem
-
-havingClause = aExpr
-
-windowClause = foldMap windowDefinition
-
-valuesClause = foldMap exprList
-
-optTempTableName _ = []
-
-groupByItem = \case
-  ExprGroupByItem a -> aExpr a
-  EmptyGroupingSetGroupByItem -> []
-  RollupGroupByItem a -> exprList a
-  CubeGroupByItem a -> exprList a
-  GroupingSetsGroupByItem a -> foldMap groupByItem a
-
-windowDefinition (WindowDefinition _ a) = windowSpecification a
-
-windowSpecification (WindowSpecification _ a b c) = foldMap (foldMap aExpr) a <> foldMap sortClause b <> foldMap frameClause c
-
-frameClause (FrameClause _ a _) = frameExtent a
-
-frameExtent = \case
-  SingularFrameExtent a -> frameBound a
-  BetweenFrameExtent a b -> frameBound a <> frameBound b
-
-frameBound = \case
-  UnboundedPrecedingFrameBound -> []
-  UnboundedFollowingFrameBound -> []
-  CurrentRowFrameBound -> []
-  PrecedingFrameBound a -> aExpr a
-  FollowingFrameBound a -> aExpr a
-
-sortClause = foldMap sortBy
-
-sortBy = \case
-  UsingSortBy a b c -> aExpr a <> qualAllOp b <> foldMap nullsOrder c
-  AscDescSortBy a b c -> aExpr a <> foldMap ascDesc b <> foldMap nullsOrder c
-
--- * Table refs
-
-tableRef = \case
-  RelationExprTableRef a b c -> relationExpr a <> foldMap aliasClause b <> foldMap tablesampleClause c
-  FuncTableRef a b c -> funcTable b <> foldMap funcAliasClause c
-  SelectTableRef _ a _ -> selectWithParens a
-  JoinTableRef a _ -> joinedTable a
-
-relationExpr = \case
-  SimpleRelationExpr a _ -> qualifiedName a
-  OnlyRelationExpr a _ -> qualifiedName a
-
-relationExprOptAlias (RelationExprOptAlias a b) = relationExpr a <> foldMap (colId . snd) b
-
-tablesampleClause (TablesampleClause a b c) = funcName a <> exprList b <> foldMap repeatableClause c
-
-repeatableClause = aExpr
-
-funcTable = \case
-  FuncExprFuncTable a b -> funcExprWindowless a <> optOrdinality b
-  RowsFromFuncTable a b -> rowsfromList a <> optOrdinality b
-
-rowsfromItem (RowsfromItem a b) = funcExprWindowless a <> foldMap colDefList b
-
-rowsfromList = foldMap rowsfromItem
-
-colDefList = tableFuncElementList
-
-optOrdinality = const []
-
-tableFuncElementList = foldMap tableFuncElement
-
-tableFuncElement (TableFuncElement a b c) = colId a <> typename b <> foldMap collateClause c
-
-collateClause = anyName
-
-aliasClause = const []
-
-funcAliasClause = \case
-  AliasFuncAliasClause a -> aliasClause a
-  AsFuncAliasClause a -> tableFuncElementList a
-  AsColIdFuncAliasClause a b -> colId a <> tableFuncElementList b
-  ColIdFuncAliasClause a b -> colId a <> tableFuncElementList b
-
-joinedTable = \case
-  InParensJoinedTable a -> joinedTable a
-  MethJoinedTable a b c -> joinMeth a <> tableRef b <> tableRef c
-
-joinMeth = \case
-  CrossJoinMeth -> []
-  QualJoinMeth _ a -> joinQual a
-  NaturalJoinMeth _ -> []
-
-joinQual = \case
-  UsingJoinQual _ -> []
-  OnJoinQual a -> aExpr a
-
-exprList = fmap AChildExpr . toList
-
-aExpr = pure . AChildExpr
-
-bExpr = pure . BChildExpr
-
-cExpr = pure . CChildExpr
-
-funcExpr = \case
-  ApplicationFuncExpr a b c d -> funcApplication a <> foldMap withinGroupClause b <> foldMap filterClause c <> foldMap overClause d
-  SubexprFuncExpr a -> funcExprCommonSubexpr a
-
-funcExprWindowless = \case
-  ApplicationFuncExprWindowless a -> funcApplication a
-  CommonSubexprFuncExprWindowless a -> funcExprCommonSubexpr a
-
-withinGroupClause = sortClause
-
-filterClause a = aExpr a
-
-overClause = \case
-  WindowOverClause a -> windowSpecification a
-  ColIdOverClause _ -> []
-
-funcExprCommonSubexpr = \case
-  CollationForFuncExprCommonSubexpr a -> aExpr a
-  CurrentDateFuncExprCommonSubexpr -> []
-  CurrentTimeFuncExprCommonSubexpr _ -> []
-  CurrentTimestampFuncExprCommonSubexpr _ -> []
-  LocalTimeFuncExprCommonSubexpr _ -> []
-  LocalTimestampFuncExprCommonSubexpr _ -> []
-  CurrentRoleFuncExprCommonSubexpr -> []
-  CurrentUserFuncExprCommonSubexpr -> []
-  SessionUserFuncExprCommonSubexpr -> []
-  UserFuncExprCommonSubexpr -> []
-  CurrentCatalogFuncExprCommonSubexpr -> []
-  CurrentSchemaFuncExprCommonSubexpr -> []
-  CastFuncExprCommonSubexpr a b -> aExpr a <> typename b
-  ExtractFuncExprCommonSubexpr a -> foldMap extractList a
-  OverlayFuncExprCommonSubexpr a -> overlayList a
-  PositionFuncExprCommonSubexpr a -> foldMap positionList a
-  SubstringFuncExprCommonSubexpr a -> foldMap substrList a
-  TreatFuncExprCommonSubexpr a b -> aExpr a <> typename b
-  TrimFuncExprCommonSubexpr a b -> foldMap trimModifier a <> trimList b
-  NullIfFuncExprCommonSubexpr a b -> aExpr a <> aExpr b
-  CoalesceFuncExprCommonSubexpr a -> exprList a
-  GreatestFuncExprCommonSubexpr a -> exprList a
-  LeastFuncExprCommonSubexpr a -> exprList a
-
-extractList (ExtractList a b) = extractArg a <> aExpr b
-
-extractArg _ = []
-
-overlayList (OverlayList a b c d) = foldMap aExpr ([a, b, c] <> toList d)
-
-positionList (PositionList a b) = bExpr a <> bExpr b
-
-substrList = \case
-  ExprSubstrList a b -> aExpr a <> substrListFromFor b
-  ExprListSubstrList a -> exprList a
-
-substrListFromFor = \case
-  FromForSubstrListFromFor a b -> aExpr a <> aExpr b
-  ForFromSubstrListFromFor a b -> aExpr a <> aExpr b
-  FromSubstrListFromFor a -> aExpr a
-  ForSubstrListFromFor a -> aExpr a
-
-trimModifier _ = []
-
-trimList = \case
-  ExprFromExprListTrimList a b -> aExpr a <> exprList b
-  FromExprListTrimList a -> exprList a
-  ExprListTrimList a -> exprList a
-
-whenClause (WhenClause a b) = aExpr a <> aExpr b
-
-funcApplication (FuncApplication a b) = funcName a <> foldMap funcApplicationParams b
-
-funcApplicationParams = \case
-  NormalFuncApplicationParams _ a b -> foldMap funcArgExpr a <> foldMap (foldMap sortBy) b
-  VariadicFuncApplicationParams a b c -> foldMap (foldMap funcArgExpr) a <> funcArgExpr b <> foldMap (foldMap sortBy) c
-  StarFuncApplicationParams -> []
-
-funcArgExpr = \case
-  ExprFuncArgExpr a -> aExpr a
-  ColonEqualsFuncArgExpr _ a -> aExpr a
-  EqualsGreaterFuncArgExpr _ a -> aExpr a
-
-caseExpr (CaseExpr a b c) = foldMap aExpr a <> whenClauseList b <> foldMap aExpr c
-
-whenClauseList = foldMap whenClause
-
-arrayExpr = \case
-  ExprListArrayExpr a -> exprList a
-  ArrayExprListArrayExpr a -> arrayExprList a
-  EmptyArrayExpr -> []
-
-arrayExprList = foldMap arrayExpr
-
-inExpr = \case
-  SelectInExpr a -> selectWithParens a
-  ExprListInExpr a -> exprList a
-
--- * Operators
-
-symbolicExprBinOp = \case
-  MathSymbolicExprBinOp a -> mathOp a
-  QualSymbolicExprBinOp a -> qualOp a
-
-qualOp = \case
-  OpQualOp a -> op a
-  OperatorQualOp a -> anyOperator a
-
-qualAllOp = \case
-  AllQualAllOp a -> allOp a
-  AnyQualAllOp a -> anyOperator a
-
-verbalExprBinOp = const []
-
-aExprReversableOp = \case
-  NullAExprReversableOp -> []
-  TrueAExprReversableOp -> []
-  FalseAExprReversableOp -> []
-  UnknownAExprReversableOp -> []
-  DistinctFromAExprReversableOp a -> aExpr a
-  OfAExprReversableOp a -> typeList a
-  BetweenAExprReversableOp a b c -> bExpr b <> aExpr c
-  BetweenSymmetricAExprReversableOp a b -> bExpr a <> aExpr b
-  InAExprReversableOp a -> inExpr a
-  DocumentAExprReversableOp -> []
-
-subqueryOp = \case
-  AllSubqueryOp a -> allOp a
-  AnySubqueryOp a -> anyOperator a
-  LikeSubqueryOp _ -> []
-  IlikeSubqueryOp _ -> []
-
-bExprIsOp = \case
-  DistinctFromBExprIsOp a -> bExpr a
-  OfBExprIsOp a -> typeList a
-  DocumentBExprIsOp -> []
-
-allOp = \case
-  OpAllOp a -> op a
-  MathAllOp a -> mathOp a
-
-anyOperator = \case
-  AllOpAnyOperator a -> allOp a
-  QualifiedAnyOperator a b -> colId a <> anyOperator b
-
-op = const []
-
-mathOp = const []
-
--- * Rows
-
-row = \case
-  ExplicitRowRow a -> explicitRow a
-  ImplicitRowRow a -> implicitRow a
-
-explicitRow = foldMap exprList
-
-implicitRow (ImplicitRow a b) = exprList a <> aExpr b
-
--- * Constants
-
-aexprConst = \case
-  IAexprConst _ -> []
-  FAexprConst _ -> []
-  SAexprConst _ -> []
-  BAexprConst _ -> []
-  XAexprConst _ -> []
-  FuncAexprConst a b _ -> funcName a <> foldMap funcConstArgs b
-  ConstTypenameAexprConst a _ -> constTypename a
-  StringIntervalAexprConst _ a -> foldMap interval a
-  IntIntervalAexprConst _ _ -> []
-  BoolAexprConst _ -> []
-  NullAexprConst -> []
-
-funcConstArgs (FuncConstArgs a b) = foldMap funcArgExpr a <> foldMap sortClause b
-
-constTypename = \case
-  NumericConstTypename a -> numeric a
-  ConstBitConstTypename a -> constBit a
-  ConstCharacterConstTypename a -> constCharacter a
-  ConstDatetimeConstTypename a -> constDatetime a
-
-numeric = \case
-  IntNumeric -> []
-  IntegerNumeric -> []
-  SmallintNumeric -> []
-  BigintNumeric -> []
-  RealNumeric -> []
-  FloatNumeric _ -> []
-  DoublePrecisionNumeric -> []
-  DecimalNumeric a -> foldMap exprList a
-  DecNumeric a -> foldMap exprList a
-  NumericNumeric a -> foldMap exprList a
-  BooleanNumeric -> []
-
-bit (Bit _ a) = foldMap exprList a
-
-constBit = bit
-
-constCharacter (ConstCharacter _ _) = []
-
-constDatetime _ = []
-
-interval _ = []
-
--- * Names
-
-ident _ = []
-
-colId = ident
-
-name = colId
-
-cursorName = name
-
-anyName (AnyName a b) = colId a <> foldMap attrs b
-
-columnref (Columnref a b) = colId a <> foldMap indirection b
-
-funcName = \case
-  TypeFuncName a -> typeFunctionName a
-  IndirectedFuncName a b -> colId a <> indirection b
-
-qualifiedName = \case
-  SimpleQualifiedName _ -> []
-  IndirectedQualifiedName _ a -> indirection a
-
-indirection = foldMap indirectionEl
-
-indirectionEl = \case
-  AttrNameIndirectionEl _ -> []
-  AllIndirectionEl -> []
-  ExprIndirectionEl a -> aExpr a
-  SliceIndirectionEl a b -> exprList a <> exprList b
-
--- * Types
-
-typeList = foldMap typename
-
-typename (Typename a b c d) =
-  simpleTypename b
-
-simpleTypename = \case
-  GenericTypeSimpleTypename a -> genericType a
-  NumericSimpleTypename a -> numeric a
-  BitSimpleTypename a -> bit a
-  CharacterSimpleTypename a -> character a
-  ConstDatetimeSimpleTypename a -> constDatetime a
-  ConstIntervalSimpleTypename a -> either (foldMap interval) (const []) a
-
-arrayBounds _ = []
-
-genericType (GenericType a b c) = typeFunctionName a <> foldMap attrs b <> foldMap typeModifiers c
-
-typeFunctionName = ident
-
-attrs = foldMap attrName
-
-attrName _ = []
-
-typeModifiers = exprList
-
-character _ = []
-
-subType _ = []
-
--- * Indexes
-
-indexParams = foldMap indexElem
-
-indexElem (IndexElem a b c d e) = indexElemDef a <> foldMap anyName b <> foldMap anyName c
-
-indexElemDef = \case
-  IdIndexElemDef a -> colId a
-  FuncIndexElemDef a -> funcExprWindowless a
-  ExprIndexElemDef a -> aExpr a
-
-ascDesc = const []
-
-nullsOrder = const []
diff --git a/library/Hasql/TH/Extraction/Exp.hs b/library/Hasql/TH/Extraction/Exp.hs
deleted file mode 100644
--- a/library/Hasql/TH/Extraction/Exp.hs
+++ /dev/null
@@ -1,112 +0,0 @@
-module Hasql.TH.Extraction.Exp where
-
-import qualified Hasql.Decoders as Decoders
-import qualified Hasql.Encoders as Encoders
-import qualified Hasql.TH.Construction.Exp as Exp
-import qualified Hasql.TH.Extraction.InputTypeList as InputTypeList
-import qualified Hasql.TH.Extraction.OutputTypeList as OutputTypeList
-import qualified Hasql.TH.Extraction.PrimitiveType as PrimitiveType
-import Hasql.TH.Prelude
-import Language.Haskell.TH
-import qualified PostgresqlSyntax.Ast as Ast
-import qualified PostgresqlSyntax.Rendering as Rendering
-
-undecodedStatement :: (Exp -> Exp) -> Ast.PreparableStmt -> Either Text Exp
-undecodedStatement _decoderProj _ast =
-  let _sql = (Exp.byteString . Rendering.toByteString . Rendering.preparableStmt) _ast
-   in do
-        _encoder <- paramsEncoder _ast
-        _rowDecoder <- rowDecoder _ast
-        return (Exp.statement _sql _encoder (_decoderProj _rowDecoder))
-
-foldStatement :: Ast.PreparableStmt -> Either Text Exp
-foldStatement _ast =
-  let _sql = (Exp.byteString . Rendering.toByteString . Rendering.preparableStmt) _ast
-   in do
-        _encoder <- paramsEncoder _ast
-        _rowDecoder <- rowDecoder _ast
-        return (Exp.foldStatement _sql _encoder _rowDecoder)
-
-paramsEncoder :: Ast.PreparableStmt -> Either Text Exp
-paramsEncoder a = do
-  b <- InputTypeList.preparableStmt a
-  c <- traverse paramEncoder b
-  return (Exp.contrazip c)
-
-rowDecoder :: Ast.PreparableStmt -> Either Text Exp
-rowDecoder a = do
-  b <- OutputTypeList.preparableStmt a
-  c <- traverse columnDecoder b
-  return (Exp.cozip c)
-
-paramEncoder :: Ast.Typename -> Either Text Exp
-paramEncoder =
-  byTypename
-    (\a b -> valueEncoder a & fmap (Exp.unidimensionalParamEncoder b))
-    (\a b c d -> valueEncoder a & fmap (Exp.multidimensionalParamEncoder b c d))
-
-columnDecoder :: Ast.Typename -> Either Text Exp
-columnDecoder =
-  byTypename
-    (\a b -> valueDecoder a & fmap (Exp.unidimensionalColumnDecoder b))
-    (\a b c d -> valueDecoder a & fmap (Exp.multidimensionalColumnDecoder b c d))
-
-byTypename :: (PrimitiveType.PrimitiveType -> Bool -> Either Text Exp) -> (PrimitiveType.PrimitiveType -> Bool -> Int -> Bool -> Either Text Exp) -> Ast.Typename -> Either Text Exp
-byTypename unidimensional multidimensional (Ast.Typename a b c d) =
-  if a
-    then Left "SETOF is not supported"
-    else do
-      e <- PrimitiveType.simpleTypename b
-      case d of
-        Nothing -> unidimensional e c
-        Just (f, g) -> case f of
-          Ast.BoundsTypenameArrayDimensions h -> multidimensional e c (length h) g
-          Ast.ExplicitTypenameArrayDimensions _ -> multidimensional e c 1 g
-
-valueEncoder :: PrimitiveType.PrimitiveType -> Either Text Exp
-valueEncoder =
-  Right . VarE . \case
-    PrimitiveType.BoolPrimitiveType -> 'Encoders.bool
-    PrimitiveType.Int2PrimitiveType -> 'Encoders.int2
-    PrimitiveType.Int4PrimitiveType -> 'Encoders.int4
-    PrimitiveType.Int8PrimitiveType -> 'Encoders.int8
-    PrimitiveType.Float4PrimitiveType -> 'Encoders.float4
-    PrimitiveType.Float8PrimitiveType -> 'Encoders.float8
-    PrimitiveType.NumericPrimitiveType -> 'Encoders.numeric
-    PrimitiveType.CharPrimitiveType -> 'Encoders.char
-    PrimitiveType.TextPrimitiveType -> 'Encoders.text
-    PrimitiveType.ByteaPrimitiveType -> 'Encoders.bytea
-    PrimitiveType.DatePrimitiveType -> 'Encoders.date
-    PrimitiveType.TimestampPrimitiveType -> 'Encoders.timestamp
-    PrimitiveType.TimestamptzPrimitiveType -> 'Encoders.timestamptz
-    PrimitiveType.TimePrimitiveType -> 'Encoders.time
-    PrimitiveType.TimetzPrimitiveType -> 'Encoders.timetz
-    PrimitiveType.IntervalPrimitiveType -> 'Encoders.interval
-    PrimitiveType.UuidPrimitiveType -> 'Encoders.uuid
-    PrimitiveType.InetPrimitiveType -> 'Encoders.inet
-    PrimitiveType.JsonPrimitiveType -> 'Encoders.json
-    PrimitiveType.JsonbPrimitiveType -> 'Encoders.jsonb
-
-valueDecoder :: PrimitiveType.PrimitiveType -> Either Text Exp
-valueDecoder =
-  Right . VarE . \case
-    PrimitiveType.BoolPrimitiveType -> 'Decoders.bool
-    PrimitiveType.Int2PrimitiveType -> 'Decoders.int2
-    PrimitiveType.Int4PrimitiveType -> 'Decoders.int4
-    PrimitiveType.Int8PrimitiveType -> 'Decoders.int8
-    PrimitiveType.Float4PrimitiveType -> 'Decoders.float4
-    PrimitiveType.Float8PrimitiveType -> 'Decoders.float8
-    PrimitiveType.NumericPrimitiveType -> 'Decoders.numeric
-    PrimitiveType.CharPrimitiveType -> 'Decoders.char
-    PrimitiveType.TextPrimitiveType -> 'Decoders.text
-    PrimitiveType.ByteaPrimitiveType -> 'Decoders.bytea
-    PrimitiveType.DatePrimitiveType -> 'Decoders.date
-    PrimitiveType.TimestampPrimitiveType -> 'Decoders.timestamp
-    PrimitiveType.TimestamptzPrimitiveType -> 'Decoders.timestamptz
-    PrimitiveType.TimePrimitiveType -> 'Decoders.time
-    PrimitiveType.TimetzPrimitiveType -> 'Decoders.timetz
-    PrimitiveType.IntervalPrimitiveType -> 'Decoders.interval
-    PrimitiveType.UuidPrimitiveType -> 'Decoders.uuid
-    PrimitiveType.InetPrimitiveType -> 'Decoders.inet
-    PrimitiveType.JsonPrimitiveType -> 'Decoders.json
-    PrimitiveType.JsonbPrimitiveType -> 'Decoders.jsonb
diff --git a/library/Hasql/TH/Extraction/InputTypeList.hs b/library/Hasql/TH/Extraction/InputTypeList.hs
deleted file mode 100644
--- a/library/Hasql/TH/Extraction/InputTypeList.hs
+++ /dev/null
@@ -1,52 +0,0 @@
--- |
--- AST traversal extracting input types.
-module Hasql.TH.Extraction.InputTypeList where
-
-import qualified Data.IntMap.Strict as IntMap
-import qualified Hasql.TH.Extraction.PlaceholderTypeMap as PlaceholderTypeMap
-import Hasql.TH.Prelude
-import PostgresqlSyntax.Ast
-
--- |
--- >>> import qualified PostgresqlSyntax.Parsing as P
--- >>> test = either fail (return . preparableStmt) . P.run P.preparableStmt
---
--- >>> test "select $1 :: INT"
--- Right [Typename False (NumericSimpleTypename IntNumeric) False Nothing]
---
--- >>> test "select $1 :: INT, a + $2 :: INTEGER"
--- Right [Typename False (NumericSimpleTypename IntNumeric) False Nothing,Typename False (NumericSimpleTypename IntegerNumeric) False Nothing]
---
--- >>> test "select $1 :: INT4"
--- Right [Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "int4") Nothing Nothing)) False Nothing]
---
--- >>> test "select $1 :: text[]?"
--- Right [Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "text") Nothing Nothing)) False (Just (BoundsTypenameArrayDimensions (Nothing :| []),True))]
---
--- >>> test "select $1 :: text?[]?"
--- Right [Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "text") Nothing Nothing)) True (Just (BoundsTypenameArrayDimensions (Nothing :| []),True))]
---
--- >>> test "select $1"
--- Left "Placeholder $1 misses an explicit typecast"
---
--- >>> test "select $2 :: int4, $1 :: int4, $2 :: int4"
--- Right [Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "int4") Nothing Nothing)) False Nothing,Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "int4") Nothing Nothing)) False Nothing]
---
--- >>> test "select $1 :: int4, $1 :: text"
--- Left "Placeholder $1 has conflicting type annotations"
---
--- >>> test "select $2 :: int4, $2 :: text"
--- Left "Placeholder $2 has conflicting type annotations"
---
--- >>> test "select $3 :: int4, $1 :: int4"
--- Left "You've missed placeholder $2"
-preparableStmt :: PreparableStmt -> Either Text [Typename]
-preparableStmt = placeholderTypeMap <=< PlaceholderTypeMap.preparableStmt
-
-placeholderTypeMap :: IntMap Typename -> Either Text [Typename]
-placeholderTypeMap a = do
-  zipWithM
-    (\a b -> if a == b then Right () else Left ("You've missed placeholder $" <> showAsText b))
-    (IntMap.keys a)
-    [1 ..]
-  return (IntMap.elems a)
diff --git a/library/Hasql/TH/Extraction/OutputTypeList.hs b/library/Hasql/TH/Extraction/OutputTypeList.hs
deleted file mode 100644
--- a/library/Hasql/TH/Extraction/OutputTypeList.hs
+++ /dev/null
@@ -1,90 +0,0 @@
-{-# OPTIONS_GHC -Wno-missing-signatures #-}
-
--- |
--- AST traversal extracting output types.
-module Hasql.TH.Extraction.OutputTypeList where
-
-import Hasql.TH.Prelude
-import PostgresqlSyntax.Ast
-
-foldable :: (Foldable f) => (a -> Either Text [Typename]) -> f a -> Either Text [Typename]
-foldable fn = fmap join . traverse fn . toList
-
-preparableStmt = \case
-  SelectPreparableStmt a -> selectStmt a
-  InsertPreparableStmt a -> insertStmt a
-  UpdatePreparableStmt a -> updateStmt a
-  DeletePreparableStmt a -> deleteStmt a
-  CallPreparableStmt a -> callStmt a
-
--- * Call
-
-callStmt (CallStmt a) =
-  Right []
-
--- * Insert
-
-insertStmt (InsertStmt a b c d e) = foldable returningClause e
-
-returningClause = targetList
-
--- * Update
-
-updateStmt (UpdateStmt _ _ _ _ _ a) = foldable returningClause a
-
--- * Delete
-
-deleteStmt (DeleteStmt _ _ _ _ a) = foldable returningClause a
-
--- * Select
-
-selectStmt = \case
-  Left a -> selectNoParens a
-  Right a -> selectWithParens a
-
-selectNoParens (SelectNoParens _ a _ _ _) = selectClause a
-
-selectWithParens = \case
-  NoParensSelectWithParens a -> selectNoParens a
-  WithParensSelectWithParens a -> selectWithParens a
-
-selectClause = either simpleSelect selectWithParens
-
-simpleSelect = \case
-  NormalSimpleSelect a _ _ _ _ _ _ -> foldable targeting a
-  ValuesSimpleSelect a -> valuesClause a
-  TableSimpleSelect _ -> Left "TABLE cannot be used as a final statement, since it's impossible to specify the output types"
-  BinSimpleSelect _ a _ b -> do
-    c <- selectClause a
-    d <- selectClause b
-    if c == d
-      then return c
-      else Left "Merged queries produce results of incompatible types"
-
-targeting = \case
-  NormalTargeting a -> targetList a
-  AllTargeting a -> foldable targetList a
-  DistinctTargeting _ b -> targetList b
-
-targetList = foldable targetEl
-
-targetEl = \case
-  AliasedExprTargetEl a _ -> aExpr a
-  ImplicitlyAliasedExprTargetEl a _ -> aExpr a
-  ExprTargetEl a -> aExpr a
-  AsteriskTargetEl ->
-    Left
-      "Target of all fields is not allowed, \
-      \because it leaves the output types unspecified. \
-      \You have to be specific."
-
-valuesClause = foldable (foldable aExpr)
-
-aExpr = \case
-  CExprAExpr a -> cExpr a
-  TypecastAExpr _ a -> Right [a]
-  a -> Left "Result expression is missing a typecast"
-
-cExpr = \case
-  InParensCExpr a Nothing -> aExpr a
-  a -> Left "Result expression is missing a typecast"
diff --git a/library/Hasql/TH/Extraction/PlaceholderTypeMap.hs b/library/Hasql/TH/Extraction/PlaceholderTypeMap.hs
deleted file mode 100644
--- a/library/Hasql/TH/Extraction/PlaceholderTypeMap.hs
+++ /dev/null
@@ -1,58 +0,0 @@
-{-# OPTIONS_GHC -Wno-missing-signatures #-}
-
-module Hasql.TH.Extraction.PlaceholderTypeMap where
-
-import qualified Data.IntMap.Strict as IntMap
-import Hasql.TH.Extraction.ChildExprList (ChildExpr (..))
-import qualified Hasql.TH.Extraction.ChildExprList as ChildExprList
-import Hasql.TH.Prelude hiding (union)
-import PostgresqlSyntax.Ast
-
-preparableStmt :: PreparableStmt -> Either Text (IntMap Typename)
-preparableStmt = childExprList . ChildExprList.preparableStmt
-
-childExprList :: [ChildExpr] -> Either Text (IntMap Typename)
-childExprList = foldM union IntMap.empty <=< traverse childExpr
-
-union :: IntMap Typename -> IntMap Typename -> Either Text (IntMap Typename)
-union a b = IntMap.mergeWithKey merge (fmap Right) (fmap Right) a b & sequence
-  where
-    merge index a b =
-      if a == b
-        then Just (Right a)
-        else Just (Left ("Placeholder $" <> (fromString . show) index <> " has conflicting type annotations"))
-
-childExpr :: ChildExpr -> Either Text (IntMap Typename)
-childExpr = \case
-  AChildExpr a -> aExpr a
-  BChildExpr a -> bExpr a
-  CChildExpr a -> cExpr a
-
-aExpr = \case
-  CExprAExpr a -> cExpr a
-  TypecastAExpr a b -> castedAExpr b a
-  a -> childExprList (ChildExprList.aChildExpr a)
-
-bExpr = \case
-  CExprBExpr a -> cExpr a
-  TypecastBExpr a b -> castedBExpr b a
-  a -> childExprList (ChildExprList.bChildExpr a)
-
-cExpr = \case
-  ParamCExpr a _ -> Left ("Placeholder $" <> (fromString . show) a <> " misses an explicit typecast")
-  a -> childExprList (ChildExprList.cChildExpr a)
-
-castedAExpr a = \case
-  CExprAExpr b -> castedCExpr a b
-  TypecastAExpr b c -> castedAExpr c b
-  b -> aExpr b
-
-castedBExpr a = \case
-  CExprBExpr b -> castedCExpr a b
-  TypecastBExpr b c -> castedBExpr c b
-  b -> bExpr b
-
-castedCExpr a = \case
-  ParamCExpr b _ -> Right (IntMap.singleton b a)
-  InParensCExpr b _ -> castedAExpr a b
-  b -> cExpr b
diff --git a/library/Hasql/TH/Extraction/PrimitiveType.hs b/library/Hasql/TH/Extraction/PrimitiveType.hs
deleted file mode 100644
--- a/library/Hasql/TH/Extraction/PrimitiveType.hs
+++ /dev/null
@@ -1,102 +0,0 @@
-{-# OPTIONS_GHC -Wno-missing-signatures #-}
-
-module Hasql.TH.Extraction.PrimitiveType where
-
-import Hasql.TH.Prelude hiding (bit, fromList, sortBy)
-import PostgresqlSyntax.Ast
-
-data PrimitiveType
-  = BoolPrimitiveType
-  | Int2PrimitiveType
-  | Int4PrimitiveType
-  | Int8PrimitiveType
-  | Float4PrimitiveType
-  | Float8PrimitiveType
-  | NumericPrimitiveType
-  | CharPrimitiveType
-  | TextPrimitiveType
-  | ByteaPrimitiveType
-  | DatePrimitiveType
-  | TimestampPrimitiveType
-  | TimestamptzPrimitiveType
-  | TimePrimitiveType
-  | TimetzPrimitiveType
-  | IntervalPrimitiveType
-  | UuidPrimitiveType
-  | InetPrimitiveType
-  | JsonPrimitiveType
-  | JsonbPrimitiveType
-
-simpleTypename = \case
-  GenericTypeSimpleTypename a -> genericType a
-  NumericSimpleTypename a -> numeric a
-  BitSimpleTypename a -> bit a
-  CharacterSimpleTypename a -> character a
-  ConstDatetimeSimpleTypename a -> constDatetime a
-  ConstIntervalSimpleTypename a -> Right IntervalPrimitiveType
-
-genericType (GenericType a b c) = case b of
-  Just _ -> Left "Type attributes are not supported"
-  Nothing -> case c of
-    Just _ -> Left "Type modifiers are not supported"
-    Nothing -> ident a
-
-numeric = \case
-  IntNumeric -> Right Int4PrimitiveType
-  IntegerNumeric -> Right Int4PrimitiveType
-  SmallintNumeric -> Right Int2PrimitiveType
-  BigintNumeric -> Right Int8PrimitiveType
-  RealNumeric -> Right Float4PrimitiveType
-  FloatNumeric a -> case a of
-    Just _ -> Left "Modifier on FLOAT is not supported"
-    Nothing -> Right Float4PrimitiveType
-  DoublePrecisionNumeric -> Right Float8PrimitiveType
-  DecimalNumeric a -> case a of
-    Just _ -> Left "Modifiers on DECIMAL are not supported"
-    Nothing -> Right NumericPrimitiveType
-  DecNumeric a -> case a of
-    Just _ -> Left "Modifiers on DEC are not supported"
-    Nothing -> Right NumericPrimitiveType
-  NumericNumeric a -> case a of
-    Just _ -> Left "Modifiers on NUMERIC are not supported"
-    Nothing -> Right NumericPrimitiveType
-  BooleanNumeric -> Right BoolPrimitiveType
-
-bit _ = Left "Bit codec is not supported"
-
-character _ = Right CharPrimitiveType
-
-constDatetime = \case
-  TimestampConstDatetime _ a -> if tz a then Right TimestamptzPrimitiveType else Right TimestampPrimitiveType
-  TimeConstDatetime _ a -> if tz a then Right TimetzPrimitiveType else Right TimePrimitiveType
-  where
-    tz = \case
-      Just a -> a
-      Nothing -> False
-
-ident = \case
-  QuotedIdent a -> name a
-  UnquotedIdent a -> name a
-
-name = \case
-  "bool" -> Right BoolPrimitiveType
-  "int2" -> Right Int2PrimitiveType
-  "int4" -> Right Int4PrimitiveType
-  "int8" -> Right Int8PrimitiveType
-  "float4" -> Right Float4PrimitiveType
-  "float8" -> Right Float8PrimitiveType
-  "numeric" -> Right NumericPrimitiveType
-  "char" -> Right CharPrimitiveType
-  "text" -> Right TextPrimitiveType
-  "bytea" -> Right ByteaPrimitiveType
-  "date" -> Right DatePrimitiveType
-  "timestamp" -> Right TimestampPrimitiveType
-  "timestamptz" -> Right TimestamptzPrimitiveType
-  "time" -> Right TimePrimitiveType
-  "timetz" -> Right TimetzPrimitiveType
-  "interval" -> Right IntervalPrimitiveType
-  "uuid" -> Right UuidPrimitiveType
-  "inet" -> Right InetPrimitiveType
-  "json" -> Right JsonPrimitiveType
-  "jsonb" -> Right JsonbPrimitiveType
-  name -> Left ("No codec exists for type: " <> name)
diff --git a/library/Hasql/TH/Prelude.hs b/library/Hasql/TH/Prelude.hs
deleted file mode 100644
--- a/library/Hasql/TH/Prelude.hs
+++ /dev/null
@@ -1,94 +0,0 @@
-module Hasql.TH.Prelude
-  ( module Exports,
-    showAsText,
-    suffixRec,
-  )
-where
-
-import Control.Applicative as Exports
-import Control.Arrow as Exports hiding (first, second)
-import Control.Category as Exports
-import Control.Concurrent as Exports
-import Control.Exception as Exports
-import Control.Foldl as Exports (Fold (..))
-import Control.Monad as Exports hiding (fail, forM, forM_, mapM, mapM_, msum, sequence, sequence_)
-import Control.Monad.Fail as Exports
-import Control.Monad.Fix as Exports hiding (fix)
-import Control.Monad.IO.Class as Exports
-import Control.Monad.ST as Exports
-import Data.Bifunctor as Exports
-import Data.Bits as Exports
-import Data.Bool as Exports
-import Data.ByteString as Exports (ByteString)
-import Data.Char as Exports
-import Data.Coerce as Exports
-import Data.Complex as Exports
-import Data.Data as Exports
-import Data.Dynamic as Exports
-import Data.Either as Exports
-import Data.Fixed as Exports
-import Data.Foldable as Exports
-import Data.Function as Exports hiding (id, (.))
-import Data.Functor as Exports hiding (unzip)
-import Data.Functor.Contravariant as Exports
-import Data.Functor.Contravariant.Divisible as Exports
-import Data.Functor.Identity as Exports
-import Data.IORef as Exports
-import Data.Int as Exports
-import Data.IntMap.Strict as Exports (IntMap)
-import Data.IntSet as Exports (IntSet)
-import Data.Ix as Exports
-import Data.List as Exports hiding (all, and, any, concat, concatMap, elem, find, foldl, foldl', foldl1, foldr, foldr1, isSubsequenceOf, mapAccumL, mapAccumR, maximum, maximumBy, minimum, minimumBy, notElem, or, product, sortOn, sum, uncons)
-import Data.List.NonEmpty as Exports (NonEmpty (..))
-import Data.Map.Strict as Exports (Map)
-import Data.Maybe as Exports
-import Data.Monoid as Exports hiding (First (..), Last (..), (<>))
-import Data.Ord as Exports
-import Data.Proxy as Exports
-import Data.Ratio as Exports
-import Data.STRef as Exports
-import Data.Semigroup as Exports
-import Data.Sequence as Exports (Seq)
-import Data.Set as Exports (Set)
-import Data.String as Exports
-import Data.Text as Exports (Text)
-import Data.Traversable as Exports
-import Data.Tuple as Exports
-import Data.UUID as Exports (UUID)
-import Data.Unique as Exports
-import Data.Version as Exports
-import Data.Void as Exports
-import Data.Word as Exports
-import Debug.Trace as Exports
-import Foreign.ForeignPtr as Exports
-import Foreign.Ptr as Exports
-import Foreign.StablePtr as Exports
-import Foreign.Storable as Exports hiding (alignment, sizeOf)
-import GHC.Conc as Exports hiding (orElse, threadWaitRead, threadWaitReadSTM, threadWaitWrite, threadWaitWriteSTM, withMVar)
-import GHC.Exts as Exports (IsList (Item, fromList), groupWith, inline, lazy, sortWith)
-import GHC.Generics as Exports (Generic, Generic1)
-import GHC.IO.Exception as Exports
-import Numeric as Exports
-import System.Environment as Exports
-import System.Exit as Exports
-import System.IO as Exports
-import System.IO.Error as Exports
-import System.IO.Unsafe as Exports
-import System.Mem as Exports
-import System.Mem.StableName as Exports
-import System.Timeout as Exports
-import Text.Printf as Exports (hPrintf, printf)
-import Text.Read as Exports (Read (..), readEither, readMaybe)
-import Unsafe.Coerce as Exports
-import Prelude as Exports hiding (all, and, any, concat, concatMap, elem, fail, foldl, foldl1, foldr, foldr1, id, mapM, mapM_, maximum, minimum, notElem, or, product, sequence, sequence_, sum, (.))
-
-showAsText :: (Show a) => a -> Text
-showAsText = show >>> fromString
-
--- |
--- Compose a monad, which attempts to extend a value, based on the following input.
--- It does that recursively until the suffix alternative fails.
-suffixRec :: (Monad m, Alternative m) => m a -> (a -> m a) -> m a
-suffixRec base suffix = do
-  _base <- base
-  suffixRec (suffix _base) suffix <|> pure _base
diff --git a/src/library/Hasql/TH.hs b/src/library/Hasql/TH.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH.hs
@@ -0,0 +1,279 @@
+module Hasql.TH
+  ( -- * Statements
+
+    -- |
+    --  Quasiquoters in this category produce Hasql `Statement`s,
+    --  checking the correctness of SQL at compile-time.
+    --
+    --  To extract the information about parameters and results of the statement,
+    --  the quoter requires you to explicitly specify the Postgres types for placeholders and results.
+    --
+    --  Here's an example of how to use it:
+    --
+    --  >selectUserDetails :: Statement Int32 (Maybe (Text, Text, Maybe Text))
+    --  >selectUserDetails =
+    --  >  [maybeStatement|
+    --  >    select name :: text, email :: text, phone :: text?
+    --  >    from "user"
+    --  >    where id = $1 :: int4
+    --  >    |]
+    --
+    --  As you can see, it completely eliminates the need to mess with codecs.
+    --  The quasiquoters directly produce `Statement`,
+    --  which you can then `Data.Profunctor.dimap` over using its `Data.Profunctor.Profunctor` instance to get to your domain types.
+    --
+    --  == Type mappings
+    --
+    --  === Primitives
+    --
+    --  Following is a list of supported Postgres types and their according types on the Haskell end.
+    --
+    --  - @bool@ - `Bool`
+    --  - @int2@ - `Int16`
+    --  - @int4@ - `Int32`
+    --  - @int8@ - `Int64`
+    --  - @float4@ - `Float`
+    --  - @float8@ - `Double`
+    --  - @numeric@ - `Data.Scientific.Scientific`
+    --  - @char@ - `Char`
+    --  - @text@ - `Data.Text.Text`
+    --  - @bytea@ - `Data.ByteString.ByteString`
+    --  - @date@ - `Data.Time.Day`
+    --  - @timestamp@ - `Data.Time.LocalTime`
+    --  - @timestamptz@ - `Data.Time.UTCTime`
+    --  - @time@ - `Data.Time.TimeOfDay`
+    --  - @timetz@ - @(`Data.Time.TimeOfDay`, `Data.Time.TimeZone`)@
+    --  - @interval@ - `Data.Time.DiffTime`
+    --  - @uuid@ - `Data.UUID.UUID`
+    --  - @inet@ - @(`Network.IP.Addr.NetAddr` `Network.IP.Addr.IP`)@
+    --  - @json@ - `Data.Aeson.Value`
+    --  - @jsonb@ - `Data.Aeson.Value`
+    --
+    --  === Arrays
+    --
+    --  Array mappings are also supported.
+    --  They are specified according to Postgres syntax: by appending one or more @[]@ to the primitive type,
+    --  depending on how many dimensions the array has.
+    --  On the Haskell end array is mapped to generic `Data.Vector.Generic.Vector`,
+    --  allowing you to choose which particular vector implementation to map to.
+    --
+    --  === Nulls
+    --
+    --  As you might have noticed in the example,
+    --  we introduce one change to the Postgres syntax in the way
+    --  the typesignatures are parsed:
+    --  we interpret question-marks in them as specification of nullability.
+    --  Here's more examples of that:
+    --
+    --  >>> :t [singletonStatement| select a :: int4? |]
+    --  ...
+    --    :: Statement () (Maybe Int32)
+    --
+    --  You can use it to specify the nullability of array elements:
+    --
+    --  >>> :t [singletonStatement| select a :: int4?[] |]
+    --  ...
+    --    :: Data.Vector.Generic.Base.Vector v (Maybe Int32) =>
+    --       Statement () (v (Maybe Int32))
+    --
+    --  And of arrays themselves:
+    --
+    --  >>> :t [singletonStatement| select a :: int4?[]? |]
+    --  ...
+    --    :: Data.Vector.Generic.Base.Vector v (Maybe Int32) =>
+    --       Statement () (Maybe (v (Maybe Int32)))
+
+    -- ** Row-parsing statements
+    singletonStatement,
+    maybeStatement,
+    vectorStatement,
+    foldStatement,
+
+    -- ** Row-ignoring statements
+    resultlessStatement,
+    rowsAffectedStatement,
+
+    -- * SQL ByteStrings
+
+    -- |
+    --  ByteString-producing quasiquoters.
+    --
+    --  For now they perform no compile-time checking.
+    uncheckedSql,
+    uncheckedSqlFile,
+  )
+where
+
+import qualified Data.Text as Text
+import qualified Data.Text.Encoding as Text
+import qualified Hasql.TH.Construction.Exp as Exp
+import qualified Hasql.TH.Extraction.Exp as ExpExtraction
+import Hasql.TH.Prelude hiding (exp)
+import Language.Haskell.TH.Quote
+import Language.Haskell.TH.Syntax
+import qualified PostgresqlSyntax.Ast as Ast
+import qualified PostgresqlSyntax.Parsing as Parsing
+
+-- * Helpers
+
+exp :: (String -> Q Exp) -> QuasiQuoter
+exp =
+  let _unsupported _ = fail "Unsupported"
+   in \_exp -> QuasiQuoter _exp _unsupported _unsupported _unsupported
+
+expParser :: (Text -> Either Text Exp) -> QuasiQuoter
+expParser _parser =
+  exp $ \_inputString -> either (fail . Text.unpack) return $ _parser $ fromString _inputString
+
+expPreparableStmtAstParser :: (Ast.PreparableStmt -> Either Text Exp) -> QuasiQuoter
+expPreparableStmtAstParser _parser =
+  expParser $ \_input -> do
+    _ast <- first fromString $ Parsing.run (Parsing.atEnd Parsing.preparableStmt) _input
+    _parser _ast
+
+-- * Statement
+
+-- |
+-- @
+-- :: `Statement` params row
+-- @
+--
+-- Statement producing exactly one result row.
+--
+-- Will cause the running session to fail with the
+-- `Hasql.Session.UnexpectedAmountOfRows` error if it's any other.
+--
+-- === __Examples__
+--
+-- >>> :t [singletonStatement|select 1 :: int2|]
+-- ... :: Statement () Int16
+--
+-- >>> :{
+--   :t [singletonStatement|
+--        insert into "user" (email, name)
+--        values ($1 :: text, $2 :: text)
+--        returning id :: int4
+--        |]
+-- :}
+-- ...
+-- ... :: Statement (Text, Text) Int32
+--
+-- Incorrect SQL:
+--
+-- >>> :t [singletonStatement|elect 1|]
+-- ...
+--   |
+-- 1 | elect 1
+--   |      ^
+-- ...
+singletonStatement :: QuasiQuoter
+singletonStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement Exp.singleRowResultDecoder)
+
+-- |
+-- @
+-- :: `Statement` params (Maybe row)
+-- @
+--
+-- Statement producing one row or none.
+--
+-- === __Examples__
+--
+-- >>> :t [maybeStatement|select 1 :: int2|]
+-- ... :: Statement () (Maybe Int16)
+maybeStatement :: QuasiQuoter
+maybeStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement Exp.rowMaybeResultDecoder)
+
+-- |
+-- @
+-- :: `Statement` params (`Vector` row)
+-- @
+--
+-- Statement producing a vector of rows.
+--
+-- === __Examples__
+--
+-- >>> :t [vectorStatement|select 1 :: int2|]
+-- ... :: Statement () (Vector Int16)
+vectorStatement :: QuasiQuoter
+vectorStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement Exp.rowVectorResultDecoder)
+
+-- |
+-- @
+-- :: `Fold` row folding -> `Statement` params folding
+-- @
+--
+-- Function from `Fold` over rows to a statement producing the result of folding.
+-- Use this when you need to aggregate rows customly.
+--
+-- === __Examples__
+--
+-- >>> :t [foldStatement|select 1 :: int2|]
+-- ... :: Fold Int16 b -> Statement () b
+foldStatement :: QuasiQuoter
+foldStatement = expPreparableStmtAstParser ExpExtraction.foldStatement
+
+-- |
+-- @
+-- :: `Statement` params ()
+-- @
+--
+-- Statement producing no results.
+--
+-- === __Examples__
+--
+-- >>> :t [resultlessStatement|insert into "user" (name, email) values ($1 :: text, $2 :: text)|]
+-- ...
+-- ... :: Statement (Text, Text) ()
+resultlessStatement :: QuasiQuoter
+resultlessStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement (const Exp.noResultResultDecoder))
+
+-- |
+-- @
+-- :: `Statement` params Int64
+-- @
+--
+-- Statement counting the rows it affects.
+--
+-- === __Examples__
+--
+-- >>> :t [rowsAffectedStatement|delete from "user" where password is null|]
+-- ...
+-- ... :: Statement () Int64
+rowsAffectedStatement :: QuasiQuoter
+rowsAffectedStatement = expPreparableStmtAstParser (ExpExtraction.undecodedStatement (const Exp.rowsAffectedResultDecoder))
+
+-- * SQL ByteStrings
+
+-- |
+-- Quoter of a multiline Unicode SQL string,
+-- which gets converted into a format ready to be used for declaration of statements.
+uncheckedSql :: QuasiQuoter
+uncheckedSql = exp $ return . Exp.byteString . Text.encodeUtf8 . fromString
+
+-- |
+-- Read an SQL-file, containing multiple statements,
+-- and produce an expression of type `ByteString`.
+--
+-- Allows to store plain SQL in external files and read it at compile time.
+--
+-- E.g.,
+--
+-- >migration1 :: Hasql.Session.Session ()
+-- >migration1 = Hasql.Session.sql [uncheckedSqlFile|migrations/1.sql|]
+uncheckedSqlFile :: QuasiQuoter
+uncheckedSqlFile = quoteFile uncheckedSql
+
+-- * Tests
+
+-- $
+-- >>> :t [maybeStatement| select (password = $2 :: bytea) :: bool, id :: int4 from "user" where "email" = $1 :: text |]
+-- ...
+-- ... Statement (Text, ByteString) (Maybe (Bool, Int32))
+--
+-- >>> :t [maybeStatement| select id :: int4 from application where pub_key = $1 :: uuid and sec_key_pt1 = $2 :: int8 and sec_key_pt2 = $3 :: int8 |]
+-- ...
+-- ... Statement (UUID, Int64, Int64) (Maybe Int32)
+--
+-- >>> :t [singletonStatement| select 1 :: int4 from a left join b on b.id = a.id |]
+-- ...
+-- ... Statement () Int32
diff --git a/src/library/Hasql/TH/Construction/Exp.hs b/src/library/Hasql/TH/Construction/Exp.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH/Construction/Exp.hs
@@ -0,0 +1,201 @@
+-- |
+-- Expression construction.
+module Hasql.TH.Construction.Exp where
+
+import qualified Data.ByteString as ByteString
+import qualified Data.ByteString.Unsafe as ByteString
+import qualified Data.Vector.Generic as Vector
+import qualified Hasql.Decoders as Decoders
+import qualified Hasql.Encoders as Encoders
+import qualified Hasql.Statement as Statement
+import Hasql.TH.Prelude hiding (sequence_)
+import qualified Hasql.TH.Prelude as Prelude
+import Language.Haskell.TH.Syntax
+import qualified TemplateHaskell.Compat.V0208 as Compat
+
+-- * Helpers
+
+appList :: Exp -> [Exp] -> Exp
+appList = foldl' AppE
+
+byteString :: ByteString -> Exp
+byteString x =
+  appList
+    (VarE 'unsafeDupablePerformIO)
+    [ appList
+        (VarE 'ByteString.unsafePackAddressLen)
+        [ LitE (IntegerL (fromIntegral (ByteString.length x))),
+          LitE (StringPrimL (ByteString.unpack x))
+        ]
+    ]
+
+integral :: (Integral a) => a -> Exp
+integral x = LitE (IntegerL (fromIntegral x))
+
+list :: (a -> Exp) -> [a] -> Exp
+list renderer x = ListE (map renderer x)
+
+string :: String -> Exp
+string x = LitE (StringL x)
+
+char :: Char -> Exp
+char x = LitE (CharL x)
+
+sequence_ :: [Exp] -> Exp
+sequence_ = foldl' andThen pureUnit
+
+pureUnit :: Exp
+pureUnit = AppE (VarE 'Prelude.pure) (TupE [])
+
+andThen :: Exp -> Exp -> Exp
+andThen exp1 exp2 = AppE (AppE (VarE '(*>)) exp1) exp2
+
+tuple :: Int -> Exp
+tuple = ConE . tupleDataName
+
+splitTupleAt :: Int -> Int -> Exp
+splitTupleAt arity position =
+  let nameByIndex index = Name (OccName ('_' : show index)) NameS
+      names = enumFromTo 0 (pred arity) & map nameByIndex
+      pats = names & map VarP
+      pat = TupP pats
+      exps = names & map VarE
+      body = splitAt position exps & \(a, b) -> Compat.tupE [Compat.tupE a, Compat.tupE b]
+   in LamE [pat] body
+
+-- |
+-- Given a list of divisible functor expressions,
+-- constructs an expression, which composes them together into
+-- a single divisible functor, parameterized by a tuple of according arity.
+contrazip :: [Exp] -> Exp
+contrazip = \case
+  _head : [] -> _head
+  _head : _tail -> appList (VarE 'divide) [splitTupleAt (succ (length _tail)) 1, _head, contrazip _tail]
+  [] ->
+    SigE
+      (VarE 'conquer)
+      ( let _fName = mkName "f"
+            _fVar = VarT _fName
+         in ForallT
+              [Compat.specifiedPlainTV _fName]
+              [AppT (ConT ''Divisible) (VarT _fName)]
+              (AppT (VarT _fName) (TupleT 0))
+      )
+
+-- |
+-- Given a list of applicative functor expressions,
+-- constructs an expression, which composes them together into
+-- a single applicative functor, parameterized by a tuple of according arity.
+--
+-- >>> $(return (cozip [])) :: Maybe ()
+-- Just ()
+--
+-- >>> $(return (cozip (fmap (AppE (ConE 'Just) . LitE . IntegerL) [1,2,3]))) :: Maybe (Int, Int, Int)
+-- Just (1,2,3)
+cozip :: [Exp] -> Exp
+cozip = \case
+  _head : [] -> _head
+  _head : _tail ->
+    let _length = length _tail + 1
+     in foldl'
+          (\a b -> AppE (AppE (VarE '(<*>)) a) b)
+          (AppE (AppE (VarE 'fmap) (tuple _length)) _head)
+          _tail
+  [] -> AppE (VarE 'pure) (TupE [])
+
+-- |
+-- Lambda expression, which destructures 'Fold'.
+foldLam :: (Exp -> Exp -> Exp -> Exp) -> Exp
+foldLam _body =
+  let _stepVarName = mkName "progress"
+      _initVarName = mkName "start"
+      _extractVarName = mkName "finish"
+   in LamE
+        [ Compat.conP
+            'Fold
+            [ VarP _stepVarName,
+              VarP _initVarName,
+              VarP _extractVarName
+            ]
+        ]
+        (_body (VarE _stepVarName) (VarE _initVarName) (VarE _extractVarName))
+
+-- * Statement
+
+statement :: Exp -> Exp -> Exp -> Exp
+statement _sql _encoder _decoder =
+  appList (VarE 'Statement.preparable) [_sql, _encoder, _decoder]
+
+noResultResultDecoder :: Exp
+noResultResultDecoder = VarE 'Decoders.noResult
+
+rowsAffectedResultDecoder :: Exp
+rowsAffectedResultDecoder = VarE 'Decoders.rowsAffected
+
+singleRowResultDecoder :: Exp -> Exp
+singleRowResultDecoder = 'Decoders.singleRow & VarE & AppE
+
+rowMaybeResultDecoder :: Exp -> Exp
+rowMaybeResultDecoder = AppE (VarE 'Decoders.rowMaybe)
+
+rowVectorResultDecoder :: Exp -> Exp
+rowVectorResultDecoder = AppE (VarE 'Decoders.rowVector)
+
+foldStatement :: Exp -> Exp -> Exp -> Exp
+foldStatement _sql _encoder _rowDecoder =
+  foldLam (\_step _init _extract -> statement _sql _encoder (foldResultDecoder _step _init _extract _rowDecoder))
+
+foldResultDecoder :: Exp -> Exp -> Exp -> Exp -> Exp
+foldResultDecoder _step _init _extract _rowDecoder =
+  appList (VarE 'fmap) [_extract, appList (VarE 'Decoders.foldlRows) [_step, _init, _rowDecoder]]
+
+unidimensionalParamEncoder :: Bool -> Exp -> Exp
+unidimensionalParamEncoder nullable =
+  applyParamToEncoder . applyNullabilityToEncoder nullable
+
+multidimensionalParamEncoder :: Bool -> Int -> Bool -> Exp -> Exp
+multidimensionalParamEncoder nullable dimensionality arrayNull =
+  applyParamToEncoder
+    . applyNullabilityToEncoder arrayNull
+    . AppE (VarE 'Encoders.array)
+    . applyArrayDimensionalityToEncoder dimensionality
+    . applyNullabilityToEncoder nullable
+
+applyParamToEncoder :: Exp -> Exp
+applyParamToEncoder = AppE (VarE 'Encoders.param)
+
+applyNullabilityToEncoder :: Bool -> Exp -> Exp
+applyNullabilityToEncoder nullable = AppE (VarE (if nullable then 'Encoders.nullable else 'Encoders.nonNullable))
+
+applyArrayDimensionalityToEncoder :: Int -> Exp -> Exp
+applyArrayDimensionalityToEncoder levels =
+  if levels > 0
+    then AppE (AppE (VarE 'Encoders.dimension) (VarE 'Vector.foldl')) . applyArrayDimensionalityToEncoder (pred levels)
+    else AppE (VarE 'Encoders.element)
+
+rowDecoder :: [Exp] -> Exp
+rowDecoder = cozip
+
+unidimensionalColumnDecoder :: Bool -> Exp -> Exp
+unidimensionalColumnDecoder nullable =
+  applyColumnToDecoder . applyNullabilityToDecoder nullable
+
+multidimensionalColumnDecoder :: Bool -> Int -> Bool -> Exp -> Exp
+multidimensionalColumnDecoder nullable dimensionality arrayNull =
+  applyColumnToDecoder
+    . applyNullabilityToDecoder arrayNull
+    . AppE (VarE 'Decoders.array)
+    . applyArrayDimensionalityToDecoder dimensionality
+    . applyNullabilityToDecoder nullable
+
+applyColumnToDecoder :: Exp -> Exp
+applyColumnToDecoder = AppE (VarE 'Decoders.column)
+
+applyNullabilityToDecoder :: Bool -> Exp -> Exp
+applyNullabilityToDecoder nullable = AppE (VarE (if nullable then 'Decoders.nullable else 'Decoders.nonNullable))
+
+applyArrayDimensionalityToDecoder :: Int -> Exp -> Exp
+applyArrayDimensionalityToDecoder levels =
+  if levels > 0
+    then AppE (AppE (VarE 'Decoders.dimension) (VarE 'Vector.replicateM)) . applyArrayDimensionalityToDecoder (pred levels)
+    else AppE (VarE 'Decoders.element)
diff --git a/src/library/Hasql/TH/Extraction/ChildExprList.hs b/src/library/Hasql/TH/Extraction/ChildExprList.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH/Extraction/ChildExprList.hs
@@ -0,0 +1,611 @@
+{-# OPTIONS_GHC -Wno-unused-binds -Wno-unused-imports -Wno-name-shadowing -Wno-incomplete-patterns -Wno-unused-matches -Wno-missing-methods -Wno-unused-record-wildcards -Wno-redundant-constraints -Wno-deprecations -Wno-missing-signatures #-}
+
+module Hasql.TH.Extraction.ChildExprList where
+
+import Hasql.TH.Prelude hiding (bit, fromList, sortBy)
+import PostgresqlSyntax.Ast
+
+-- * Types
+
+data ChildExpr = AChildExpr AExpr | BChildExpr BExpr | CChildExpr CExpr
+  deriving (Show, Eq, Ord)
+
+-- |
+-- Dives one level of recursion.
+childExpr = \case
+  AChildExpr a -> aChildExpr a
+  BChildExpr a -> bChildExpr a
+  CChildExpr a -> cChildExpr a
+
+aChildExpr = \case
+  CExprAExpr a -> cChildExpr a
+  TypecastAExpr a b -> aExpr a <> typename b
+  CollateAExpr a b -> aExpr a <> anyName b
+  AtTimeZoneAExpr a b -> aExpr a <> aExpr b
+  PlusAExpr a -> aExpr a
+  MinusAExpr a -> aExpr a
+  SymbolicBinOpAExpr a b c -> aExpr a <> symbolicExprBinOp b <> aExpr c
+  PrefixQualOpAExpr a b -> qualOp a <> aExpr b
+  SuffixQualOpAExpr a b -> aExpr a <> qualOp b
+  AndAExpr a b -> aExpr a <> aExpr b
+  OrAExpr a b -> aExpr a <> aExpr b
+  NotAExpr a -> aExpr a
+  VerbalExprBinOpAExpr a b c d e -> aExpr a <> verbalExprBinOp c <> aExpr d <> foldMap aExpr e
+  ReversableOpAExpr a b c -> aExpr a <> aExprReversableOp c
+  IsnullAExpr a -> aExpr a
+  NotnullAExpr a -> aExpr a
+  OverlapsAExpr a b -> row a <> row b
+  SubqueryAExpr a b c d -> aExpr a <> subqueryOp b <> subType c <> either selectWithParens aExpr d
+  UniqueAExpr a -> selectWithParens a
+  DefaultAExpr -> []
+
+bChildExpr = \case
+  CExprBExpr a -> cChildExpr a
+  TypecastBExpr a b -> bExpr a <> typename b
+  PlusBExpr a -> bExpr a
+  MinusBExpr a -> bExpr a
+  SymbolicBinOpBExpr a b c -> bExpr a <> symbolicExprBinOp b <> bExpr c
+  QualOpBExpr a b -> qualOp a <> bExpr b
+  IsOpBExpr a b c -> bExpr a <> bExprIsOp c
+
+cChildExpr = \case
+  ColumnrefCExpr a -> columnref a
+  AexprConstCExpr a -> aexprConst a
+  ParamCExpr a b -> foldMap indirection b
+  InParensCExpr a b -> aExpr a <> foldMap indirection b
+  CaseCExpr a -> caseExpr a
+  FuncCExpr a -> funcExpr a
+  SelectWithParensCExpr a b -> selectWithParens a <> foldMap indirection b
+  ExistsCExpr a -> selectWithParens a
+  ArrayCExpr a -> either selectWithParens arrayExpr a
+  ExplicitRowCExpr a -> explicitRow a
+  ImplicitRowCExpr a -> implicitRow a
+  GroupingCExpr a -> exprList a
+
+preparableStmt = \case
+  SelectPreparableStmt a -> selectStmt a
+  InsertPreparableStmt a -> insertStmt a
+  UpdatePreparableStmt a -> updateStmt a
+  DeletePreparableStmt a -> deleteStmt a
+  CallPreparableStmt a -> callStmt a
+
+-- * Call
+
+callStmt (CallStmt a) = funcApplication a
+
+-- * Insert
+
+insertStmt (InsertStmt a b c d e) =
+  foldMap withClause a
+    <> insertTarget b
+    <> insertRest c
+    <> foldMap onConflict d
+    <> foldMap returningClause e
+
+insertTarget (InsertTarget a b) = qualifiedName a <> colId b
+
+insertRest = \case
+  SelectInsertRest a b c -> foldMap insertColumnList a <> foldMap overrideKind b <> selectStmt c
+  DefaultValuesInsertRest -> []
+
+overrideKind _ = []
+
+insertColumnList = foldMap insertColumnItem
+
+insertColumnItem (InsertColumnItem a b) = colId a <> foldMap indirection b
+
+onConflict (OnConflict a b) = foldMap confExpr a <> onConflictDo b
+
+onConflictDo = \case
+  UpdateOnConflictDo b c -> setClauseList b <> foldMap whereClause c
+  NothingOnConflictDo -> []
+
+confExpr = \case
+  WhereConfExpr a b -> indexParams a <> foldMap whereClause b
+  ConstraintConfExpr a -> name a
+
+returningClause = targetList
+
+-- * Update
+
+updateStmt (UpdateStmt a b c d e f) =
+  foldMap withClause a
+    <> relationExprOptAlias b
+    <> setClauseList c
+    <> foldMap fromClause d
+    <> foldMap whereOrCurrentClause e
+    <> foldMap returningClause f
+
+setClauseList = foldMap setClause
+
+setClause = \case
+  TargetSetClause a b -> setTarget a <> aExpr b
+  TargetListSetClause a b -> setTargetList a <> aExpr b
+
+setTarget (SetTarget a b) = colId a <> foldMap indirection b
+
+setTargetList = foldMap setTarget
+
+-- * Delete
+
+deleteStmt (DeleteStmt a b c d e) =
+  foldMap withClause a
+    <> relationExprOptAlias b
+    <> foldMap usingClause c
+    <> foldMap whereOrCurrentClause d
+    <> foldMap returningClause e
+
+usingClause = fromList
+
+-- * Select
+
+selectStmt = \case
+  Left a -> selectNoParens a
+  Right a -> selectWithParens a
+
+selectNoParens (SelectNoParens a b c d e) =
+  foldMap withClause a
+    <> selectClause b
+    <> foldMap sortClause c
+    <> foldMap selectLimit d
+    <> foldMap forLockingClause e
+
+selectWithParens = \case
+  NoParensSelectWithParens a -> selectNoParens a
+  WithParensSelectWithParens a -> selectWithParens a
+
+withClause (WithClause _ a) = foldMap commonTableExpr a
+
+commonTableExpr (CommonTableExpr a b c d) = preparableStmt d
+
+selectLimit = \case
+  LimitOffsetSelectLimit a b -> limitClause a <> offsetClause b
+  OffsetLimitSelectLimit a b -> offsetClause a <> limitClause b
+  LimitSelectLimit a -> limitClause a
+  OffsetSelectLimit a -> offsetClause a
+
+limitClause = \case
+  LimitLimitClause a b -> selectLimitValue a <> exprList b
+  FetchOnlyLimitClause a b c -> foldMap selectFetchFirstValue b
+
+offsetClause = \case
+  ExprOffsetClause a -> aExpr a
+  FetchFirstOffsetClause a b -> selectFetchFirstValue a
+
+selectFetchFirstValue = \case
+  ExprSelectFetchFirstValue a -> cExpr a
+  NumSelectFetchFirstValue _ _ -> []
+
+selectLimitValue = \case
+  ExprSelectLimitValue a -> aExpr a
+  AllSelectLimitValue -> []
+
+forLockingClause = \case
+  ItemsForLockingClause a -> foldMap forLockingItem a
+  ReadOnlyForLockingClause -> []
+
+forLockingItem (ForLockingItem a b c) =
+  foldMap (foldMap qualifiedName) b
+
+selectClause = either simpleSelect selectWithParens
+
+simpleSelect = \case
+  NormalSimpleSelect a b c d e f g ->
+    foldMap targeting a
+      <> foldMap intoClause b
+      <> foldMap fromClause c
+      <> foldMap whereClause d
+      <> foldMap groupClause e
+      <> foldMap havingClause f
+      <> foldMap windowClause g
+  ValuesSimpleSelect a -> valuesClause a
+  TableSimpleSelect a -> relationExpr a
+  BinSimpleSelect _ a _ b -> selectClause a <> selectClause b
+
+targeting = \case
+  NormalTargeting a -> foldMap targetEl a
+  AllTargeting a -> foldMap (foldMap targetEl) a
+  DistinctTargeting a b -> foldMap exprList a <> foldMap targetEl b
+
+targetList = foldMap targetEl
+
+targetEl = \case
+  AliasedExprTargetEl a _ -> aExpr a
+  ImplicitlyAliasedExprTargetEl a _ -> aExpr a
+  ExprTargetEl a -> aExpr a
+  AsteriskTargetEl -> []
+
+intoClause = optTempTableName
+
+fromClause = fromList
+
+fromList = foldMap tableRef
+
+whereClause = aExpr
+
+whereOrCurrentClause = \case
+  ExprWhereOrCurrentClause a -> aExpr a
+  CursorWhereOrCurrentClause a -> cursorName a
+
+groupClause = foldMap groupByItem
+
+havingClause = aExpr
+
+windowClause = foldMap windowDefinition
+
+valuesClause = foldMap exprList
+
+optTempTableName _ = []
+
+groupByItem = \case
+  ExprGroupByItem a -> aExpr a
+  EmptyGroupingSetGroupByItem -> []
+  RollupGroupByItem a -> exprList a
+  CubeGroupByItem a -> exprList a
+  GroupingSetsGroupByItem a -> foldMap groupByItem a
+
+windowDefinition (WindowDefinition _ a) = windowSpecification a
+
+windowSpecification (WindowSpecification _ a b c) = foldMap (foldMap aExpr) a <> foldMap sortClause b <> foldMap frameClause c
+
+frameClause (FrameClause _ a _) = frameExtent a
+
+frameExtent = \case
+  SingularFrameExtent a -> frameBound a
+  BetweenFrameExtent a b -> frameBound a <> frameBound b
+
+frameBound = \case
+  UnboundedPrecedingFrameBound -> []
+  UnboundedFollowingFrameBound -> []
+  CurrentRowFrameBound -> []
+  PrecedingFrameBound a -> aExpr a
+  FollowingFrameBound a -> aExpr a
+
+sortClause = foldMap sortBy
+
+sortBy = \case
+  UsingSortBy a b c -> aExpr a <> qualAllOp b <> foldMap nullsOrder c
+  AscDescSortBy a b c -> aExpr a <> foldMap ascDesc b <> foldMap nullsOrder c
+
+-- * Table refs
+
+tableRef = \case
+  RelationExprTableRef a b c -> relationExpr a <> foldMap aliasClause b <> foldMap tablesampleClause c
+  FuncTableRef a b c -> funcTable b <> foldMap funcAliasClause c
+  SelectTableRef _ a _ -> selectWithParens a
+  JoinTableRef a _ -> joinedTable a
+
+relationExpr = \case
+  SimpleRelationExpr a _ -> qualifiedName a
+  OnlyRelationExpr a _ -> qualifiedName a
+
+relationExprOptAlias (RelationExprOptAlias a b) = relationExpr a <> foldMap (colId . snd) b
+
+tablesampleClause (TablesampleClause a b c) = funcName a <> exprList b <> foldMap repeatableClause c
+
+repeatableClause = aExpr
+
+funcTable = \case
+  FuncExprFuncTable a b -> funcExprWindowless a <> optOrdinality b
+  RowsFromFuncTable a b -> rowsfromList a <> optOrdinality b
+
+rowsfromItem (RowsfromItem a b) = funcExprWindowless a <> foldMap colDefList b
+
+rowsfromList = foldMap rowsfromItem
+
+colDefList = tableFuncElementList
+
+optOrdinality = const []
+
+tableFuncElementList = foldMap tableFuncElement
+
+tableFuncElement (TableFuncElement a b c) = colId a <> typename b <> foldMap collateClause c
+
+collateClause = anyName
+
+aliasClause = const []
+
+funcAliasClause = \case
+  AliasFuncAliasClause a -> aliasClause a
+  AsFuncAliasClause a -> tableFuncElementList a
+  AsColIdFuncAliasClause a b -> colId a <> tableFuncElementList b
+  ColIdFuncAliasClause a b -> colId a <> tableFuncElementList b
+
+joinedTable = \case
+  InParensJoinedTable a -> joinedTable a
+  MethJoinedTable a b c -> joinMeth a <> tableRef b <> tableRef c
+
+joinMeth = \case
+  CrossJoinMeth -> []
+  QualJoinMeth _ a -> joinQual a
+  NaturalJoinMeth _ -> []
+
+joinQual = \case
+  UsingJoinQual _ -> []
+  OnJoinQual a -> aExpr a
+
+exprList = fmap AChildExpr . toList
+
+aExpr = pure . AChildExpr
+
+bExpr = pure . BChildExpr
+
+cExpr = pure . CChildExpr
+
+funcExpr = \case
+  ApplicationFuncExpr a b c d -> funcApplication a <> foldMap withinGroupClause b <> foldMap filterClause c <> foldMap overClause d
+  SubexprFuncExpr a -> funcExprCommonSubexpr a
+
+funcExprWindowless = \case
+  ApplicationFuncExprWindowless a -> funcApplication a
+  CommonSubexprFuncExprWindowless a -> funcExprCommonSubexpr a
+
+withinGroupClause = sortClause
+
+filterClause a = aExpr a
+
+overClause = \case
+  WindowOverClause a -> windowSpecification a
+  ColIdOverClause _ -> []
+
+funcExprCommonSubexpr = \case
+  CollationForFuncExprCommonSubexpr a -> aExpr a
+  CurrentDateFuncExprCommonSubexpr -> []
+  CurrentTimeFuncExprCommonSubexpr _ -> []
+  CurrentTimestampFuncExprCommonSubexpr _ -> []
+  LocalTimeFuncExprCommonSubexpr _ -> []
+  LocalTimestampFuncExprCommonSubexpr _ -> []
+  CurrentRoleFuncExprCommonSubexpr -> []
+  CurrentUserFuncExprCommonSubexpr -> []
+  SessionUserFuncExprCommonSubexpr -> []
+  UserFuncExprCommonSubexpr -> []
+  CurrentCatalogFuncExprCommonSubexpr -> []
+  CurrentSchemaFuncExprCommonSubexpr -> []
+  CastFuncExprCommonSubexpr a b -> aExpr a <> typename b
+  ExtractFuncExprCommonSubexpr a -> foldMap extractList a
+  OverlayFuncExprCommonSubexpr a -> overlayList a
+  PositionFuncExprCommonSubexpr a -> foldMap positionList a
+  SubstringFuncExprCommonSubexpr a -> foldMap substrList a
+  TreatFuncExprCommonSubexpr a b -> aExpr a <> typename b
+  TrimFuncExprCommonSubexpr a b -> foldMap trimModifier a <> trimList b
+  NullIfFuncExprCommonSubexpr a b -> aExpr a <> aExpr b
+  CoalesceFuncExprCommonSubexpr a -> exprList a
+  GreatestFuncExprCommonSubexpr a -> exprList a
+  LeastFuncExprCommonSubexpr a -> exprList a
+
+extractList (ExtractList a b) = extractArg a <> aExpr b
+
+extractArg _ = []
+
+overlayList (OverlayList a b c d) = foldMap aExpr ([a, b, c] <> toList d)
+
+positionList (PositionList a b) = bExpr a <> bExpr b
+
+substrList = \case
+  ExprSubstrList a b -> aExpr a <> substrListFromFor b
+  ExprListSubstrList a -> exprList a
+
+substrListFromFor = \case
+  FromForSubstrListFromFor a b -> aExpr a <> aExpr b
+  ForFromSubstrListFromFor a b -> aExpr a <> aExpr b
+  FromSubstrListFromFor a -> aExpr a
+  ForSubstrListFromFor a -> aExpr a
+
+trimModifier _ = []
+
+trimList = \case
+  ExprFromExprListTrimList a b -> aExpr a <> exprList b
+  FromExprListTrimList a -> exprList a
+  ExprListTrimList a -> exprList a
+
+whenClause (WhenClause a b) = aExpr a <> aExpr b
+
+funcApplication (FuncApplication a b) = funcName a <> foldMap funcApplicationParams b
+
+funcApplicationParams = \case
+  NormalFuncApplicationParams _ a b -> foldMap funcArgExpr a <> foldMap (foldMap sortBy) b
+  VariadicFuncApplicationParams a b c -> foldMap (foldMap funcArgExpr) a <> funcArgExpr b <> foldMap (foldMap sortBy) c
+  StarFuncApplicationParams -> []
+
+funcArgExpr = \case
+  ExprFuncArgExpr a -> aExpr a
+  ColonEqualsFuncArgExpr _ a -> aExpr a
+  EqualsGreaterFuncArgExpr _ a -> aExpr a
+
+caseExpr (CaseExpr a b c) = foldMap aExpr a <> whenClauseList b <> foldMap aExpr c
+
+whenClauseList = foldMap whenClause
+
+arrayExpr = \case
+  ExprListArrayExpr a -> exprList a
+  ArrayExprListArrayExpr a -> arrayExprList a
+  EmptyArrayExpr -> []
+
+arrayExprList = foldMap arrayExpr
+
+inExpr = \case
+  SelectInExpr a -> selectWithParens a
+  ExprListInExpr a -> exprList a
+
+-- * Operators
+
+symbolicExprBinOp = \case
+  MathSymbolicExprBinOp a -> mathOp a
+  QualSymbolicExprBinOp a -> qualOp a
+
+qualOp = \case
+  OpQualOp a -> op a
+  OperatorQualOp a -> anyOperator a
+
+qualAllOp = \case
+  AllQualAllOp a -> allOp a
+  AnyQualAllOp a -> anyOperator a
+
+verbalExprBinOp = const []
+
+aExprReversableOp = \case
+  NullAExprReversableOp -> []
+  TrueAExprReversableOp -> []
+  FalseAExprReversableOp -> []
+  UnknownAExprReversableOp -> []
+  DistinctFromAExprReversableOp a -> aExpr a
+  OfAExprReversableOp a -> typeList a
+  BetweenAExprReversableOp a b c -> bExpr b <> aExpr c
+  BetweenSymmetricAExprReversableOp a b -> bExpr a <> aExpr b
+  InAExprReversableOp a -> inExpr a
+  DocumentAExprReversableOp -> []
+
+subqueryOp = \case
+  AllSubqueryOp a -> allOp a
+  AnySubqueryOp a -> anyOperator a
+  LikeSubqueryOp _ -> []
+  IlikeSubqueryOp _ -> []
+
+bExprIsOp = \case
+  DistinctFromBExprIsOp a -> bExpr a
+  OfBExprIsOp a -> typeList a
+  DocumentBExprIsOp -> []
+
+allOp = \case
+  OpAllOp a -> op a
+  MathAllOp a -> mathOp a
+
+anyOperator = \case
+  AllOpAnyOperator a -> allOp a
+  QualifiedAnyOperator a b -> colId a <> anyOperator b
+
+op = const []
+
+mathOp = const []
+
+-- * Rows
+
+row = \case
+  ExplicitRowRow a -> explicitRow a
+  ImplicitRowRow a -> implicitRow a
+
+explicitRow = foldMap exprList
+
+implicitRow (ImplicitRow a b) = exprList a <> aExpr b
+
+-- * Constants
+
+aexprConst = \case
+  IAexprConst _ -> []
+  FAexprConst _ -> []
+  SAexprConst _ -> []
+  BAexprConst _ -> []
+  XAexprConst _ -> []
+  FuncAexprConst a b _ -> funcName a <> foldMap funcConstArgs b
+  ConstTypenameAexprConst a _ -> constTypename a
+  StringIntervalAexprConst _ a -> foldMap interval a
+  IntIntervalAexprConst _ _ -> []
+  BoolAexprConst _ -> []
+  NullAexprConst -> []
+
+funcConstArgs (FuncConstArgs a b) = foldMap funcArgExpr a <> foldMap sortClause b
+
+constTypename = \case
+  NumericConstTypename a -> numeric a
+  ConstBitConstTypename a -> constBit a
+  ConstCharacterConstTypename a -> constCharacter a
+  ConstDatetimeConstTypename a -> constDatetime a
+
+numeric = \case
+  IntNumeric -> []
+  IntegerNumeric -> []
+  SmallintNumeric -> []
+  BigintNumeric -> []
+  RealNumeric -> []
+  FloatNumeric _ -> []
+  DoublePrecisionNumeric -> []
+  DecimalNumeric a -> foldMap exprList a
+  DecNumeric a -> foldMap exprList a
+  NumericNumeric a -> foldMap exprList a
+  BooleanNumeric -> []
+
+bit (Bit _ a) = foldMap exprList a
+
+constBit = bit
+
+constCharacter (ConstCharacter _ _) = []
+
+constDatetime _ = []
+
+interval _ = []
+
+-- * Names
+
+ident _ = []
+
+colId = ident
+
+name = colId
+
+cursorName = name
+
+anyName (AnyName a b) = colId a <> foldMap attrs b
+
+columnref (Columnref a b) = colId a <> foldMap indirection b
+
+funcName = \case
+  TypeFuncName a -> typeFunctionName a
+  IndirectedFuncName a b -> colId a <> indirection b
+
+qualifiedName = \case
+  SimpleQualifiedName _ -> []
+  IndirectedQualifiedName _ a -> indirection a
+
+indirection = foldMap indirectionEl
+
+indirectionEl = \case
+  AttrNameIndirectionEl _ -> []
+  AllIndirectionEl -> []
+  ExprIndirectionEl a -> aExpr a
+  SliceIndirectionEl a b -> exprList a <> exprList b
+
+-- * Types
+
+typeList = foldMap typename
+
+typename (Typename a b c d) =
+  simpleTypename b
+
+simpleTypename = \case
+  GenericTypeSimpleTypename a -> genericType a
+  NumericSimpleTypename a -> numeric a
+  BitSimpleTypename a -> bit a
+  CharacterSimpleTypename a -> character a
+  ConstDatetimeSimpleTypename a -> constDatetime a
+  ConstIntervalSimpleTypename a -> either (foldMap interval) (const []) a
+
+arrayBounds _ = []
+
+genericType (GenericType a b c) = typeFunctionName a <> foldMap attrs b <> foldMap typeModifiers c
+
+typeFunctionName = ident
+
+attrs = foldMap attrName
+
+attrName _ = []
+
+typeModifiers = exprList
+
+character _ = []
+
+subType _ = []
+
+-- * Indexes
+
+indexParams = foldMap indexElem
+
+indexElem (IndexElem a b c d e) = indexElemDef a <> foldMap anyName b <> foldMap anyName c
+
+indexElemDef = \case
+  IdIndexElemDef a -> colId a
+  FuncIndexElemDef a -> funcExprWindowless a
+  ExprIndexElemDef a -> aExpr a
+
+ascDesc = const []
+
+nullsOrder = const []
diff --git a/src/library/Hasql/TH/Extraction/Exp.hs b/src/library/Hasql/TH/Extraction/Exp.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH/Extraction/Exp.hs
@@ -0,0 +1,112 @@
+module Hasql.TH.Extraction.Exp where
+
+import qualified Hasql.Decoders as Decoders
+import qualified Hasql.Encoders as Encoders
+import qualified Hasql.TH.Construction.Exp as Exp
+import qualified Hasql.TH.Extraction.InputTypeList as InputTypeList
+import qualified Hasql.TH.Extraction.OutputTypeList as OutputTypeList
+import qualified Hasql.TH.Extraction.PrimitiveType as PrimitiveType
+import Hasql.TH.Prelude
+import Language.Haskell.TH
+import qualified PostgresqlSyntax.Ast as Ast
+import qualified PostgresqlSyntax.Rendering as Rendering
+
+undecodedStatement :: (Exp -> Exp) -> Ast.PreparableStmt -> Either Text Exp
+undecodedStatement _decoderProj _ast =
+  let _sql = (Exp.byteString . Rendering.toByteString . Rendering.preparableStmt) _ast
+   in do
+        _encoder <- paramsEncoder _ast
+        _rowDecoder <- rowDecoder _ast
+        return (Exp.statement _sql _encoder (_decoderProj _rowDecoder))
+
+foldStatement :: Ast.PreparableStmt -> Either Text Exp
+foldStatement _ast =
+  let _sql = (Exp.byteString . Rendering.toByteString . Rendering.preparableStmt) _ast
+   in do
+        _encoder <- paramsEncoder _ast
+        _rowDecoder <- rowDecoder _ast
+        return (Exp.foldStatement _sql _encoder _rowDecoder)
+
+paramsEncoder :: Ast.PreparableStmt -> Either Text Exp
+paramsEncoder a = do
+  b <- InputTypeList.preparableStmt a
+  c <- traverse paramEncoder b
+  return (Exp.contrazip c)
+
+rowDecoder :: Ast.PreparableStmt -> Either Text Exp
+rowDecoder a = do
+  b <- OutputTypeList.preparableStmt a
+  c <- traverse columnDecoder b
+  return (Exp.cozip c)
+
+paramEncoder :: Ast.Typename -> Either Text Exp
+paramEncoder =
+  byTypename
+    (\a b -> valueEncoder a & fmap (Exp.unidimensionalParamEncoder b))
+    (\a b c d -> valueEncoder a & fmap (Exp.multidimensionalParamEncoder b c d))
+
+columnDecoder :: Ast.Typename -> Either Text Exp
+columnDecoder =
+  byTypename
+    (\a b -> valueDecoder a & fmap (Exp.unidimensionalColumnDecoder b))
+    (\a b c d -> valueDecoder a & fmap (Exp.multidimensionalColumnDecoder b c d))
+
+byTypename :: (PrimitiveType.PrimitiveType -> Bool -> Either Text Exp) -> (PrimitiveType.PrimitiveType -> Bool -> Int -> Bool -> Either Text Exp) -> Ast.Typename -> Either Text Exp
+byTypename unidimensional multidimensional (Ast.Typename a b c d) =
+  if a
+    then Left "SETOF is not supported"
+    else do
+      e <- PrimitiveType.simpleTypename b
+      case d of
+        Nothing -> unidimensional e c
+        Just (f, g) -> case f of
+          Ast.BoundsTypenameArrayDimensions h -> multidimensional e c (length h) g
+          Ast.ExplicitTypenameArrayDimensions _ -> multidimensional e c 1 g
+
+valueEncoder :: PrimitiveType.PrimitiveType -> Either Text Exp
+valueEncoder =
+  Right . VarE . \case
+    PrimitiveType.BoolPrimitiveType -> 'Encoders.bool
+    PrimitiveType.Int2PrimitiveType -> 'Encoders.int2
+    PrimitiveType.Int4PrimitiveType -> 'Encoders.int4
+    PrimitiveType.Int8PrimitiveType -> 'Encoders.int8
+    PrimitiveType.Float4PrimitiveType -> 'Encoders.float4
+    PrimitiveType.Float8PrimitiveType -> 'Encoders.float8
+    PrimitiveType.NumericPrimitiveType -> 'Encoders.numeric
+    PrimitiveType.CharPrimitiveType -> 'Encoders.char
+    PrimitiveType.TextPrimitiveType -> 'Encoders.text
+    PrimitiveType.ByteaPrimitiveType -> 'Encoders.bytea
+    PrimitiveType.DatePrimitiveType -> 'Encoders.date
+    PrimitiveType.TimestampPrimitiveType -> 'Encoders.timestamp
+    PrimitiveType.TimestamptzPrimitiveType -> 'Encoders.timestamptz
+    PrimitiveType.TimePrimitiveType -> 'Encoders.time
+    PrimitiveType.TimetzPrimitiveType -> 'Encoders.timetz
+    PrimitiveType.IntervalPrimitiveType -> 'Encoders.interval
+    PrimitiveType.UuidPrimitiveType -> 'Encoders.uuid
+    PrimitiveType.InetPrimitiveType -> 'Encoders.inet
+    PrimitiveType.JsonPrimitiveType -> 'Encoders.json
+    PrimitiveType.JsonbPrimitiveType -> 'Encoders.jsonb
+
+valueDecoder :: PrimitiveType.PrimitiveType -> Either Text Exp
+valueDecoder =
+  Right . VarE . \case
+    PrimitiveType.BoolPrimitiveType -> 'Decoders.bool
+    PrimitiveType.Int2PrimitiveType -> 'Decoders.int2
+    PrimitiveType.Int4PrimitiveType -> 'Decoders.int4
+    PrimitiveType.Int8PrimitiveType -> 'Decoders.int8
+    PrimitiveType.Float4PrimitiveType -> 'Decoders.float4
+    PrimitiveType.Float8PrimitiveType -> 'Decoders.float8
+    PrimitiveType.NumericPrimitiveType -> 'Decoders.numeric
+    PrimitiveType.CharPrimitiveType -> 'Decoders.char
+    PrimitiveType.TextPrimitiveType -> 'Decoders.text
+    PrimitiveType.ByteaPrimitiveType -> 'Decoders.bytea
+    PrimitiveType.DatePrimitiveType -> 'Decoders.date
+    PrimitiveType.TimestampPrimitiveType -> 'Decoders.timestamp
+    PrimitiveType.TimestamptzPrimitiveType -> 'Decoders.timestamptz
+    PrimitiveType.TimePrimitiveType -> 'Decoders.time
+    PrimitiveType.TimetzPrimitiveType -> 'Decoders.timetz
+    PrimitiveType.IntervalPrimitiveType -> 'Decoders.interval
+    PrimitiveType.UuidPrimitiveType -> 'Decoders.uuid
+    PrimitiveType.InetPrimitiveType -> 'Decoders.inet
+    PrimitiveType.JsonPrimitiveType -> 'Decoders.json
+    PrimitiveType.JsonbPrimitiveType -> 'Decoders.jsonb
diff --git a/src/library/Hasql/TH/Extraction/InputTypeList.hs b/src/library/Hasql/TH/Extraction/InputTypeList.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH/Extraction/InputTypeList.hs
@@ -0,0 +1,52 @@
+-- |
+-- AST traversal extracting input types.
+module Hasql.TH.Extraction.InputTypeList where
+
+import qualified Data.IntMap.Strict as IntMap
+import qualified Hasql.TH.Extraction.PlaceholderTypeMap as PlaceholderTypeMap
+import Hasql.TH.Prelude
+import PostgresqlSyntax.Ast
+
+-- |
+-- >>> import qualified PostgresqlSyntax.Parsing as P
+-- >>> test = either fail (return . preparableStmt) . P.run P.preparableStmt
+--
+-- >>> test "select $1 :: INT"
+-- Right [Typename False (NumericSimpleTypename IntNumeric) False Nothing]
+--
+-- >>> test "select $1 :: INT, a + $2 :: INTEGER"
+-- Right [Typename False (NumericSimpleTypename IntNumeric) False Nothing,Typename False (NumericSimpleTypename IntegerNumeric) False Nothing]
+--
+-- >>> test "select $1 :: INT4"
+-- Right [Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "int4") Nothing Nothing)) False Nothing]
+--
+-- >>> test "select $1 :: text[]?"
+-- Right [Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "text") Nothing Nothing)) False (Just (BoundsTypenameArrayDimensions (Nothing :| []),True))]
+--
+-- >>> test "select $1 :: text?[]?"
+-- Right [Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "text") Nothing Nothing)) True (Just (BoundsTypenameArrayDimensions (Nothing :| []),True))]
+--
+-- >>> test "select $1"
+-- Left "Placeholder $1 misses an explicit typecast"
+--
+-- >>> test "select $2 :: int4, $1 :: int4, $2 :: int4"
+-- Right [Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "int4") Nothing Nothing)) False Nothing,Typename False (GenericTypeSimpleTypename (GenericType (UnquotedIdent "int4") Nothing Nothing)) False Nothing]
+--
+-- >>> test "select $1 :: int4, $1 :: text"
+-- Left "Placeholder $1 has conflicting type annotations"
+--
+-- >>> test "select $2 :: int4, $2 :: text"
+-- Left "Placeholder $2 has conflicting type annotations"
+--
+-- >>> test "select $3 :: int4, $1 :: int4"
+-- Left "You've missed placeholder $2"
+preparableStmt :: PreparableStmt -> Either Text [Typename]
+preparableStmt = placeholderTypeMap <=< PlaceholderTypeMap.preparableStmt
+
+placeholderTypeMap :: IntMap Typename -> Either Text [Typename]
+placeholderTypeMap a = do
+  zipWithM
+    (\a b -> if a == b then Right () else Left ("You've missed placeholder $" <> showAsText b))
+    (IntMap.keys a)
+    [1 ..]
+  return (IntMap.elems a)
diff --git a/src/library/Hasql/TH/Extraction/OutputTypeList.hs b/src/library/Hasql/TH/Extraction/OutputTypeList.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH/Extraction/OutputTypeList.hs
@@ -0,0 +1,90 @@
+{-# OPTIONS_GHC -Wno-unused-binds -Wno-unused-imports -Wno-name-shadowing -Wno-incomplete-patterns -Wno-unused-matches -Wno-missing-methods -Wno-unused-record-wildcards -Wno-redundant-constraints -Wno-deprecations -Wno-missing-signatures #-}
+
+-- |
+-- AST traversal extracting output types.
+module Hasql.TH.Extraction.OutputTypeList where
+
+import Hasql.TH.Prelude
+import PostgresqlSyntax.Ast
+
+foldable :: (Foldable f) => (a -> Either Text [Typename]) -> f a -> Either Text [Typename]
+foldable fn = fmap join . traverse fn . toList
+
+preparableStmt = \case
+  SelectPreparableStmt a -> selectStmt a
+  InsertPreparableStmt a -> insertStmt a
+  UpdatePreparableStmt a -> updateStmt a
+  DeletePreparableStmt a -> deleteStmt a
+  CallPreparableStmt a -> callStmt a
+
+-- * Call
+
+callStmt (CallStmt a) =
+  Right []
+
+-- * Insert
+
+insertStmt (InsertStmt a b c d e) = foldable returningClause e
+
+returningClause = targetList
+
+-- * Update
+
+updateStmt (UpdateStmt _ _ _ _ _ a) = foldable returningClause a
+
+-- * Delete
+
+deleteStmt (DeleteStmt _ _ _ _ a) = foldable returningClause a
+
+-- * Select
+
+selectStmt = \case
+  Left a -> selectNoParens a
+  Right a -> selectWithParens a
+
+selectNoParens (SelectNoParens _ a _ _ _) = selectClause a
+
+selectWithParens = \case
+  NoParensSelectWithParens a -> selectNoParens a
+  WithParensSelectWithParens a -> selectWithParens a
+
+selectClause = either simpleSelect selectWithParens
+
+simpleSelect = \case
+  NormalSimpleSelect a _ _ _ _ _ _ -> foldable targeting a
+  ValuesSimpleSelect a -> valuesClause a
+  TableSimpleSelect _ -> Left "TABLE cannot be used as a final statement, since it's impossible to specify the output types"
+  BinSimpleSelect _ a _ b -> do
+    c <- selectClause a
+    d <- selectClause b
+    if c == d
+      then return c
+      else Left "Merged queries produce results of incompatible types"
+
+targeting = \case
+  NormalTargeting a -> targetList a
+  AllTargeting a -> foldable targetList a
+  DistinctTargeting _ b -> targetList b
+
+targetList = foldable targetEl
+
+targetEl = \case
+  AliasedExprTargetEl a _ -> aExpr a
+  ImplicitlyAliasedExprTargetEl a _ -> aExpr a
+  ExprTargetEl a -> aExpr a
+  AsteriskTargetEl ->
+    Left
+      "Target of all fields is not allowed, \
+      \because it leaves the output types unspecified. \
+      \You have to be specific."
+
+valuesClause = foldable (foldable aExpr)
+
+aExpr = \case
+  CExprAExpr a -> cExpr a
+  TypecastAExpr _ a -> Right [a]
+  a -> Left "Result expression is missing a typecast"
+
+cExpr = \case
+  InParensCExpr a Nothing -> aExpr a
+  a -> Left "Result expression is missing a typecast"
diff --git a/src/library/Hasql/TH/Extraction/PlaceholderTypeMap.hs b/src/library/Hasql/TH/Extraction/PlaceholderTypeMap.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH/Extraction/PlaceholderTypeMap.hs
@@ -0,0 +1,58 @@
+{-# OPTIONS_GHC -Wno-missing-signatures #-}
+
+module Hasql.TH.Extraction.PlaceholderTypeMap where
+
+import qualified Data.IntMap.Strict as IntMap
+import Hasql.TH.Extraction.ChildExprList (ChildExpr (..))
+import qualified Hasql.TH.Extraction.ChildExprList as ChildExprList
+import Hasql.TH.Prelude hiding (union)
+import PostgresqlSyntax.Ast
+
+preparableStmt :: PreparableStmt -> Either Text (IntMap Typename)
+preparableStmt = childExprList . ChildExprList.preparableStmt
+
+childExprList :: [ChildExpr] -> Either Text (IntMap Typename)
+childExprList = foldM union IntMap.empty <=< traverse childExpr
+
+union :: IntMap Typename -> IntMap Typename -> Either Text (IntMap Typename)
+union a b = IntMap.mergeWithKey merge (fmap Right) (fmap Right) a b & sequence
+  where
+    merge index a b =
+      if a == b
+        then Just (Right a)
+        else Just (Left ("Placeholder $" <> (fromString . show) index <> " has conflicting type annotations"))
+
+childExpr :: ChildExpr -> Either Text (IntMap Typename)
+childExpr = \case
+  AChildExpr a -> aExpr a
+  BChildExpr a -> bExpr a
+  CChildExpr a -> cExpr a
+
+aExpr = \case
+  CExprAExpr a -> cExpr a
+  TypecastAExpr a b -> castedAExpr b a
+  a -> childExprList (ChildExprList.aChildExpr a)
+
+bExpr = \case
+  CExprBExpr a -> cExpr a
+  TypecastBExpr a b -> castedBExpr b a
+  a -> childExprList (ChildExprList.bChildExpr a)
+
+cExpr = \case
+  ParamCExpr a _ -> Left ("Placeholder $" <> (fromString . show) a <> " misses an explicit typecast")
+  a -> childExprList (ChildExprList.cChildExpr a)
+
+castedAExpr a = \case
+  CExprAExpr b -> castedCExpr a b
+  TypecastAExpr b c -> castedAExpr c b
+  b -> aExpr b
+
+castedBExpr a = \case
+  CExprBExpr b -> castedCExpr a b
+  TypecastBExpr b c -> castedBExpr c b
+  b -> bExpr b
+
+castedCExpr a = \case
+  ParamCExpr b _ -> Right (IntMap.singleton b a)
+  InParensCExpr b _ -> castedAExpr a b
+  b -> cExpr b
diff --git a/src/library/Hasql/TH/Extraction/PrimitiveType.hs b/src/library/Hasql/TH/Extraction/PrimitiveType.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH/Extraction/PrimitiveType.hs
@@ -0,0 +1,102 @@
+{-# OPTIONS_GHC -Wno-unused-binds -Wno-unused-imports -Wno-name-shadowing -Wno-incomplete-patterns -Wno-unused-matches -Wno-missing-methods -Wno-unused-record-wildcards -Wno-redundant-constraints -Wno-deprecations -Wno-missing-signatures #-}
+
+module Hasql.TH.Extraction.PrimitiveType where
+
+import Hasql.TH.Prelude hiding (bit, fromList, sortBy)
+import PostgresqlSyntax.Ast
+
+data PrimitiveType
+  = BoolPrimitiveType
+  | Int2PrimitiveType
+  | Int4PrimitiveType
+  | Int8PrimitiveType
+  | Float4PrimitiveType
+  | Float8PrimitiveType
+  | NumericPrimitiveType
+  | CharPrimitiveType
+  | TextPrimitiveType
+  | ByteaPrimitiveType
+  | DatePrimitiveType
+  | TimestampPrimitiveType
+  | TimestamptzPrimitiveType
+  | TimePrimitiveType
+  | TimetzPrimitiveType
+  | IntervalPrimitiveType
+  | UuidPrimitiveType
+  | InetPrimitiveType
+  | JsonPrimitiveType
+  | JsonbPrimitiveType
+
+simpleTypename = \case
+  GenericTypeSimpleTypename a -> genericType a
+  NumericSimpleTypename a -> numeric a
+  BitSimpleTypename a -> bit a
+  CharacterSimpleTypename a -> character a
+  ConstDatetimeSimpleTypename a -> constDatetime a
+  ConstIntervalSimpleTypename a -> Right IntervalPrimitiveType
+
+genericType (GenericType a b c) = case b of
+  Just _ -> Left "Type attributes are not supported"
+  Nothing -> case c of
+    Just _ -> Left "Type modifiers are not supported"
+    Nothing -> ident a
+
+numeric = \case
+  IntNumeric -> Right Int4PrimitiveType
+  IntegerNumeric -> Right Int4PrimitiveType
+  SmallintNumeric -> Right Int2PrimitiveType
+  BigintNumeric -> Right Int8PrimitiveType
+  RealNumeric -> Right Float4PrimitiveType
+  FloatNumeric a -> case a of
+    Just _ -> Left "Modifier on FLOAT is not supported"
+    Nothing -> Right Float4PrimitiveType
+  DoublePrecisionNumeric -> Right Float8PrimitiveType
+  DecimalNumeric a -> case a of
+    Just _ -> Left "Modifiers on DECIMAL are not supported"
+    Nothing -> Right NumericPrimitiveType
+  DecNumeric a -> case a of
+    Just _ -> Left "Modifiers on DEC are not supported"
+    Nothing -> Right NumericPrimitiveType
+  NumericNumeric a -> case a of
+    Just _ -> Left "Modifiers on NUMERIC are not supported"
+    Nothing -> Right NumericPrimitiveType
+  BooleanNumeric -> Right BoolPrimitiveType
+
+bit _ = Left "Bit codec is not supported"
+
+character _ = Right CharPrimitiveType
+
+constDatetime = \case
+  TimestampConstDatetime _ a -> if tz a then Right TimestamptzPrimitiveType else Right TimestampPrimitiveType
+  TimeConstDatetime _ a -> if tz a then Right TimetzPrimitiveType else Right TimePrimitiveType
+  where
+    tz = \case
+      Just a -> a
+      Nothing -> False
+
+ident = \case
+  QuotedIdent a -> name a
+  UnquotedIdent a -> name a
+
+name = \case
+  "bool" -> Right BoolPrimitiveType
+  "int2" -> Right Int2PrimitiveType
+  "int4" -> Right Int4PrimitiveType
+  "int8" -> Right Int8PrimitiveType
+  "float4" -> Right Float4PrimitiveType
+  "float8" -> Right Float8PrimitiveType
+  "numeric" -> Right NumericPrimitiveType
+  "char" -> Right CharPrimitiveType
+  "text" -> Right TextPrimitiveType
+  "bytea" -> Right ByteaPrimitiveType
+  "date" -> Right DatePrimitiveType
+  "timestamp" -> Right TimestampPrimitiveType
+  "timestamptz" -> Right TimestamptzPrimitiveType
+  "time" -> Right TimePrimitiveType
+  "timetz" -> Right TimetzPrimitiveType
+  "interval" -> Right IntervalPrimitiveType
+  "uuid" -> Right UuidPrimitiveType
+  "inet" -> Right InetPrimitiveType
+  "json" -> Right JsonPrimitiveType
+  "jsonb" -> Right JsonbPrimitiveType
+  name -> Left ("No codec exists for type: " <> name)
diff --git a/src/library/Hasql/TH/Prelude.hs b/src/library/Hasql/TH/Prelude.hs
new file mode 100644
--- /dev/null
+++ b/src/library/Hasql/TH/Prelude.hs
@@ -0,0 +1,94 @@
+module Hasql.TH.Prelude
+  ( module Exports,
+    showAsText,
+    suffixRec,
+  )
+where
+
+import Control.Applicative as Exports
+import Control.Arrow as Exports hiding (first, second)
+import Control.Category as Exports
+import Control.Concurrent as Exports
+import Control.Exception as Exports
+import Control.Foldl as Exports (Fold (..))
+import Control.Monad as Exports hiding (fail, forM, forM_, mapM, mapM_, msum, sequence, sequence_)
+import Control.Monad.Fail as Exports
+import Control.Monad.Fix as Exports hiding (fix)
+import Control.Monad.IO.Class as Exports
+import Control.Monad.ST as Exports
+import Data.Bifunctor as Exports
+import Data.Bits as Exports
+import Data.Bool as Exports
+import Data.ByteString as Exports (ByteString)
+import Data.Char as Exports
+import Data.Coerce as Exports
+import Data.Complex as Exports
+import Data.Data as Exports
+import Data.Dynamic as Exports
+import Data.Either as Exports
+import Data.Fixed as Exports
+import Data.Foldable as Exports
+import Data.Function as Exports hiding (id, (.))
+import Data.Functor as Exports hiding (unzip)
+import Data.Functor.Contravariant as Exports
+import Data.Functor.Contravariant.Divisible as Exports
+import Data.Functor.Identity as Exports
+import Data.IORef as Exports
+import Data.Int as Exports
+import Data.IntMap.Strict as Exports (IntMap)
+import Data.IntSet as Exports (IntSet)
+import Data.Ix as Exports
+import Data.List as Exports hiding (all, and, any, concat, concatMap, elem, find, foldl, foldl', foldl1, foldr, foldr1, isSubsequenceOf, mapAccumL, mapAccumR, maximum, maximumBy, minimum, minimumBy, notElem, or, product, sortOn, sum, uncons)
+import Data.List.NonEmpty as Exports (NonEmpty (..))
+import Data.Map.Strict as Exports (Map)
+import Data.Maybe as Exports
+import Data.Monoid as Exports hiding (First (..), Last (..), (<>))
+import Data.Ord as Exports
+import Data.Proxy as Exports
+import Data.Ratio as Exports
+import Data.STRef as Exports
+import Data.Semigroup as Exports
+import Data.Sequence as Exports (Seq)
+import Data.Set as Exports (Set)
+import Data.String as Exports
+import Data.Text as Exports (Text)
+import Data.Traversable as Exports
+import Data.Tuple as Exports
+import Data.UUID as Exports (UUID)
+import Data.Unique as Exports
+import Data.Version as Exports
+import Data.Void as Exports
+import Data.Word as Exports
+import Debug.Trace as Exports
+import Foreign.ForeignPtr as Exports
+import Foreign.Ptr as Exports
+import Foreign.StablePtr as Exports
+import Foreign.Storable as Exports hiding (alignment, sizeOf)
+import GHC.Conc as Exports hiding (orElse, threadWaitRead, threadWaitReadSTM, threadWaitWrite, threadWaitWriteSTM, withMVar)
+import GHC.Exts as Exports (IsList (Item, fromList), groupWith, inline, lazy, sortWith)
+import GHC.Generics as Exports (Generic, Generic1)
+import GHC.IO.Exception as Exports
+import Numeric as Exports
+import System.Environment as Exports
+import System.Exit as Exports
+import System.IO as Exports
+import System.IO.Error as Exports
+import System.IO.Unsafe as Exports
+import System.Mem as Exports
+import System.Mem.StableName as Exports
+import System.Timeout as Exports
+import Text.Printf as Exports (hPrintf, printf)
+import Text.Read as Exports (Read (..), readEither, readMaybe)
+import Unsafe.Coerce as Exports
+import Prelude as Exports hiding (all, and, any, concat, concatMap, elem, fail, foldl, foldl1, foldr, foldr1, id, mapM, mapM_, maximum, minimum, notElem, or, product, sequence, sequence_, sum, (.))
+
+showAsText :: (Show a) => a -> Text
+showAsText = show >>> fromString
+
+-- |
+-- Compose a monad, which attempts to extend a value, based on the following input.
+-- It does that recursively until the suffix alternative fails.
+suffixRec :: (Monad m, Alternative m) => m a -> (a -> m a) -> m a
+suffixRec base suffix = do
+  _base <- base
+  suffixRec (suffix _base) suffix <|> pure _base