{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeFamilies #-}
module Database.Groundhog.Postgresql
( withPostgresqlPool,
withPostgresqlConn,
createPostgresqlPool,
runDbConn,
Postgresql (..),
module Database.Groundhog,
module Database.Groundhog.Generic.Sql.Functions,
explicitType,
castType,
distinctOn,
-- other
showSqlType,
)
where
import Control.Arrow (second, (***))
import Control.Exception (throw)
import Control.Monad (forM, liftM2, (>=>))
import Control.Monad.IO.Class (MonadIO (..))
import Control.Monad.Trans.Class (lift)
import Control.Monad.Trans.Control (MonadBaseControl)
import Control.Monad.Trans.Reader (ask)
import Control.Monad.Trans.State (mapStateT)
import Data.Acquire (mkAcquire)
-- work around for no Semigroup instance of PG.Query prior to
-- postgresql-simple 0.5.3.0
import qualified Data.ByteString as B
import Data.ByteString.Char8 (copy, pack, unpack)
import Data.Char (isAlphaNum, isSpace, toUpper)
import Data.Function (on)
import Data.IORef
import Data.Int (Int64)
import Data.List (groupBy, intercalate, isPrefixOf, stripPrefix)
import Data.Maybe (fromJust, fromMaybe, isJust, mapMaybe)
import Data.Pool
import Data.Time.LocalTime (localTimeToUTC, utc)
import Database.Groundhog
import Database.Groundhog.Core
import Database.Groundhog.Expression
import Database.Groundhog.Generic
import Database.Groundhog.Generic.Migration hiding (MigrationPack (..))
import qualified Database.Groundhog.Generic.Migration as GM
import qualified Database.Groundhog.Generic.PersistBackendHelpers as H
import Database.Groundhog.Generic.Sql
import Database.Groundhog.Generic.Sql.Functions
import qualified Database.PostgreSQL.LibPQ as LibPQ
import qualified Database.PostgreSQL.Simple as PG
import qualified Database.PostgreSQL.Simple.FromField as PGFF
import qualified Database.PostgreSQL.Simple.Internal as PG
import Database.PostgreSQL.Simple.Ok (Ok (..))
import qualified Database.PostgreSQL.Simple.ToField as PGTF
import qualified Database.PostgreSQL.Simple.Types as PG
-- typical operations for connection: OPEN, BEGIN, COMMIT, ROLLBACK, CLOSE
newtype Postgresql = Postgresql PG.Connection
instance DbDescriptor Postgresql where
type AutoKeyType Postgresql = Int64
type QueryRaw Postgresql = Snippet Postgresql
backendName _ = "postgresql"
instance SqlDb Postgresql where
append a b = mkExpr $ operator 50 "||" a b
signum' x = mkExpr $ function "sign" [toExpr x]
quotRem' x y = (mkExpr $ operator 70 "/" x y, mkExpr $ operator 70 "%" x y)
equalsOperator a b = a <> " IS NOT DISTINCT FROM " <> b
notEqualsOperator a b = a <> " IS DISTINCT FROM " <> b
instance FloatingSqlDb Postgresql where
log' x = mkExpr $ function "ln" [toExpr x]
logBase' b x = log (liftExpr x) / log (liftExpr b)
instance PersistBackendConn Postgresql where
insert v = runDb' $ insert' v
insert_ v = runDb' $ insert_' v
insertBy u v = runDb' $ H.insertBy renderConfig queryRaw' True u v
insertByAll v = runDb' $ H.insertByAll renderConfig queryRaw' True v
replace k v = runDb' $ H.replace renderConfig queryRaw' executeRaw' (insertIntoConstructorTable False) k v
replaceBy k v = runDb' $ H.replaceBy renderConfig executeRaw' k v
select options = runDb' $ H.select renderConfig queryRaw' preColumns "" options
selectStream options = runDb' $ H.selectStream renderConfig queryRaw' preColumns "" options
selectAll = runDb' $ H.selectAll renderConfig queryRaw'
selectAllStream = runDb' $ H.selectAllStream renderConfig queryRaw'
get k = runDb' $ H.get renderConfig queryRaw' k
getBy k = runDb' $ H.getBy renderConfig queryRaw' k
update upds cond = runDb' $ H.update renderConfig executeRaw' upds cond
delete cond = runDb' $ H.delete renderConfig executeRaw' cond
deleteBy k = runDb' $ H.deleteBy renderConfig executeRaw' k
deleteAll v = runDb' $ H.deleteAll renderConfig executeRaw' v
count cond = runDb' $ H.count renderConfig queryRaw' cond
countAll fakeV = runDb' $ H.countAll renderConfig queryRaw' fakeV
project p options = runDb' $ H.project renderConfig queryRaw' preColumns "" p options
projectStream p options = runDb' $ H.projectStream renderConfig queryRaw' preColumns "" p options
migrate fakeV = mapStateT runDb' $ migrate' fakeV
executeRaw _ query ps = runDb' $ executeRaw' (fromString query) ps
queryRaw _ query ps = runDb' $ queryRaw' (fromString query) ps
insertList l = runDb' $ insertList' l
getList k = runDb' $ getList' k
instance SchemaAnalyzer Postgresql where
schemaExists schema = runDb' $ queryRaw' "SELECT 1 FROM pg_catalog.pg_namespace WHERE nspname=?" [toPrimitivePersistValue schema] >>= firstRow >>= pure . isJust
getCurrentSchema = runDb' $ queryRaw' "SELECT current_schema()" [] >>= firstRow >>= pure . (>>= fst . fromPurePersistValues)
listTables schema = runDb' $ queryRaw' "SELECT table_name FROM information_schema.tables WHERE table_schema=coalesce(?,current_schema())" [toPrimitivePersistValue schema] >>= mapStream (pure . fst . fromPurePersistValues) >>= streamToList
listTableTriggers name = runDb' $ queryRaw' "SELECT trigger_name FROM information_schema.triggers WHERE event_object_schema=coalesce(?,current_schema()) AND event_object_table=?" (toPurePersistValues name []) >>= mapStream (pure . fst . fromPurePersistValues) >>= streamToList
analyzeTable = runDb' . analyzeTable'
analyzeTrigger name = runDb' $ do
x <- queryRaw' "SELECT action_statement FROM information_schema.triggers WHERE trigger_schema=coalesce(?,current_schema()) AND trigger_name=?" (toPurePersistValues name []) >>= firstRow
pure $ case x of
Nothing -> Nothing
Just src -> fst $ fromPurePersistValues src
analyzeFunction name = runDb' $ do
let query =
"SELECT arg_types.typname, arg_types.typndims, arg_types_te.typname, ret.typname, ret.typndims, ret_te.typname, p.prosrc\
\ FROM pg_catalog.pg_namespace n\
\ INNER JOIN pg_catalog.pg_proc p ON p.pronamespace = n.oid\
\ LEFT JOIN (SELECT oid, unnest(coalesce(proallargtypes, proargtypes)) as arg FROM pg_catalog.pg_proc) as args ON p.oid = args.oid\
\ LEFT JOIN pg_type arg_types ON arg_types.oid = args.arg\
\ LEFT JOIN pg_type arg_types_te ON arg_types_te.oid = arg_types.typelem\
\ INNER JOIN pg_type ret ON p.prorettype = ret.oid\
\ LEFT JOIN pg_type ret_te ON ret_te.oid = ret.typelem\
\ WHERE n.nspname = coalesce(?,current_schema()) AND p.proname = ?"
result <- queryRaw' query (toPurePersistValues name []) >>= mapStream (pure . fst . fromPurePersistValues) >>= streamToList
let read' (typ, arr) = readSqlType typ (Nothing, Nothing, Nothing, Nothing, Nothing) arr
pure $ case result of
[] -> Nothing
((_, (ret, src)) : _) -> Just (Just $ map read' args, Just $ read' ret, src)
where
args = mapMaybe (\(typ, arr) -> fmap (\typ' -> (typ', arr)) typ) $ map fst result
getMigrationPack = fmap (migrationPack . fromJust) getCurrentSchema
withPostgresqlPool ::
(MonadBaseControl IO m, MonadIO m) =>
-- | connection string in keyword\/value format like "host=localhost port=5432 dbname=mydb". For more details and options see http://www.postgresql.org/docs/9.4/static/libpq-connect.html#LIBPQ-PARAMKEYWORDS
String ->
-- | number of connections to open
Int ->
(Pool Postgresql -> m a) ->
m a
withPostgresqlPool s connCount f = createPostgresqlPool s connCount >>= f
withPostgresqlConn ::
(MonadBaseControl IO m, MonadIO m) =>
-- | connection string
String ->
(Postgresql -> m a) ->
m a
withPostgresqlConn s = bracket (liftIO $ open' s) (liftIO . close')
createPostgresqlPool ::
MonadIO m =>
-- | connection string
String ->
-- | number of connections to open
Int ->
m (Pool Postgresql)
createPostgresqlPool s connCount = liftIO $ createPool (open' s) close' 1 20 connCount
-- Not sure of the best way to handle Semigroup/Monoid changes in ghc 8.4
-- here. It appears that the long SQL query text interferes with the use
-- of CPP here.
--
-- Manually copying over https://github.com/lpsmith/postgresql-simple/commit/44c0bb8dec3b71e8daefe104cf643c0c4fb26768#diff-75d19972de474bc8fa181e4733f3f0d6R94
-- but this is not really a good idea.
--
combine :: PG.Query -> PG.Query -> PG.Query
-- combine = (<>)
combine (PG.Query a) (PG.Query b) = PG.Query (B.append a b)
instance Savepoint Postgresql where
withConnSavepoint name m (Postgresql c) = do
let name' = fromString name
_ <- liftIO $ PG.execute_ c $ "SAVEPOINT " `combine` name'
x <- onException m (liftIO $ PG.execute_ c $ "ROLLBACK TO SAVEPOINT " `combine` name')
_ <- liftIO $ PG.execute_ c $ "RELEASE SAVEPOINT" `combine` name'
pure x
instance ConnectionManager Postgresql where
withConn f conn@(Postgresql c) = do
liftIO $ PG.begin c
x <- onException (f conn) (liftIO $ PG.rollback c)
liftIO $ PG.commit c
pure x
instance TryConnectionManager Postgresql where
tryWithConn f g conn@(Postgresql c) = do
liftIO $ PG.begin c
x <- g (f conn)
case x of
Left _ -> liftIO $ PG.rollback c
Right _ -> liftIO $ PG.commit c
pure x
instance ExtractConnection Postgresql Postgresql where
extractConn f conn = f conn
instance ExtractConnection (Pool Postgresql) Postgresql where
extractConn f pconn = withResource pconn f
open' :: String -> IO Postgresql
open' s = do
conn <- PG.connectPostgreSQL $ pack s
_ <- PG.execute_ conn $ getStatement "SET client_min_messages TO WARNING"
pure $ Postgresql conn
close' :: Postgresql -> IO ()
close' (Postgresql conn) = PG.close conn
insert' :: (PersistEntity v) => v -> Action Postgresql (AutoKey v)
insert' v = do
-- constructor number and the rest of the field values
vals <- toEntityPersistValues' v
let e = entityDef proxy v
let constructorNum = fromPrimitivePersistValue (head vals)
fmap fst $
if isSimple (constructors e)
then do
let constr = head $ constructors e
let RenderS query vals' = insertIntoConstructorTable True False (tableName escapeS e constr) constr (tail vals)
case constrAutoKeyName constr of
Nothing -> executeRaw' query (vals' []) >> pureFromPersistValue []
Just _ -> do
x <- queryRaw' query (vals' []) >>= firstRow
case x of
Just xs -> pureFromPersistValue xs
Nothing -> pureFromPersistValue []
else do
let constr = constructors e !! constructorNum
let query = "INSERT INTO " <> mainTableName escapeS e <> "(discr)VALUES(?)RETURNING(id)"
rowid <- queryRaw' query (take 1 vals) >>= getKey
let RenderS cQuery vals' = insertIntoConstructorTable False True (tableName escapeS e constr) constr (rowid : tail vals)
executeRaw' cQuery (vals' [])
pureFromPersistValue [rowid]
insert_' :: (PersistEntity v) => v -> Action Postgresql ()
insert_' v = do
-- constructor number and the rest of the field values
vals <- toEntityPersistValues' v
let e = entityDef proxy v
let constructorNum = fromPrimitivePersistValue (head vals)
if isSimple (constructors e)
then do
let constr = head $ constructors e
let RenderS query vals' = insertIntoConstructorTable False False (tableName escapeS e constr) constr (tail vals)
executeRaw' query (vals' [])
else do
let constr = constructors e !! constructorNum
let query = "INSERT INTO " <> mainTableName escapeS e <> "(discr)VALUES(?)RETURNING(id)"
rowid <- queryRaw' query (take 1 vals) >>= getKey
let RenderS cQuery vals' = insertIntoConstructorTable False True (tableName escapeS e constr) constr (rowid : tail vals)
executeRaw' cQuery (vals' [])
insertIntoConstructorTable :: Bool -> Bool -> Utf8 -> ConstructorDef -> [PersistValue] -> RenderS db r
insertIntoConstructorTable withRet withId tName c vals = RenderS query vals'
where
query = "INSERT INTO " <> tName <> columnsValues <> returning
(fields, returning) = case constrAutoKeyName c of
Just idName -> (fields', returning')
where
fields' = if withId then (idName, dbType proxy (0 :: Int64)) : constrParams c else constrParams c
returning' = if withRet then " RETURNING(" <> escapeS (fromString idName) <> ")" else mempty
_ -> (constrParams c, mempty)
columnsValues = case foldr (flatten escapeS) [] fields of
[] -> " DEFAULT VALUES"
xs -> "(" <> commasJoin xs <> ") VALUES(" <> placeholders <> ")"
RenderS placeholders vals' = commasJoin $ map renderPersistValue vals
insertList' :: forall a. PersistField a => [a] -> Action Postgresql Int64
insertList' (l :: [a]) = do
let mainName = "List" <> delim' <> delim' <> fromString (persistName (undefined :: a))
k <- queryRaw' ("INSERT INTO " <> escapeS mainName <> " DEFAULT VALUES RETURNING(id)") [] >>= getKey
let valuesName = mainName <> delim' <> "values"
let fields = [("ord", dbType proxy (0 :: Int)), ("value", dbType proxy (undefined :: a))]
let query = "INSERT INTO " <> escapeS valuesName <> "(id," <> renderFields escapeS fields <> ")VALUES(?," <> renderFields (const $ fromChar '?') fields <> ")"
let go :: Int -> [a] -> Action Postgresql ()
go n (x : xs) = do
x' <- toPersistValues x
executeRaw' query $ (k :) . (toPrimitivePersistValue n :) . x' $ []
go (n + 1) xs
go _ [] = pure ()
go 0 l
pure $ fromPrimitivePersistValue k
getList' :: forall a. PersistField a => Int64 -> Action Postgresql [a]
getList' k = do
let mainName = "List" <> delim' <> delim' <> fromString (persistName (undefined :: a))
let valuesName = mainName <> delim' <> "values"
let value = ("value", dbType proxy (undefined :: a))
let query = "SELECT " <> renderFields escapeS [value] <> " FROM " <> escapeS valuesName <> " WHERE id=? ORDER BY ord"
queryRaw' query [toPrimitivePersistValue k] >>= mapStream (fmap fst . fromPersistValues) >>= streamToList
--TODO: consider removal
getKey :: RowStream [PersistValue] -> Action Postgresql PersistValue
getKey stream = firstRow stream >>= \(Just [k]) -> pure k
----------
executeRaw' :: Utf8 -> [PersistValue] -> Action Postgresql ()
executeRaw' query vals = do
-- $logDebugS "SQL" $ fromString $ show (fromUtf8 query) ++ " " ++ show vals
Postgresql conn <- ask
let stmt = getStatement query
liftIO $ do
_ <- PG.execute conn stmt (map P vals)
pure ()
renderConfig :: RenderConfig
renderConfig =
RenderConfig
{ esc = escapeS
}
escapeS :: Utf8 -> Utf8
escapeS a = let q = fromChar '"' in q <> a <> q
delim' :: Utf8
delim' = fromChar delim
toEntityPersistValues' :: PersistEntity v => v -> Action Postgresql [PersistValue]
toEntityPersistValues' = fmap ($ []) . toEntityPersistValues
--- MIGRATION
migrate' :: (PersistEntity v) => v -> Migration (Action Postgresql)
migrate' v = do
migPack <- lift getMigrationPack
migrateRecursively (migrateSchema migPack) (migrateEntity migPack) (migrateList migPack) v
migrationPack :: String -> GM.MigrationPack Postgresql
migrationPack currentSchema = m
where
m =
GM.MigrationPack
compareTypes
(compareRefs currentSchema)
compareUniqs
compareDefaults
migTriggerOnDelete
migTriggerOnUpdate
(GM.defaultMigConstr m)
escape
"BIGSERIAL PRIMARY KEY UNIQUE"
mainTableId
defaultPriority
(\uniques refs -> ([], map AddUnique uniques ++ map AddReference refs))
showSqlType
showColumn
showAlterDb
NoAction
NoAction
showColumn :: Column -> String
showColumn (Column n nu t def) =
concat
[ escape n,
" ",
showSqlType t,
" ",
if nu then "NULL" else "NOT NULL",
case def of
Nothing -> ""
Just s -> " DEFAULT " ++ s
]
migTriggerOnDelete :: QualifiedName -> [(String, String)] -> Action Postgresql (Bool, [AlterDB])
migTriggerOnDelete tName deletes = do
let funcName = tName
trigName = tName
func <- analyzeFunction funcName
trig <- analyzeTrigger trigName
let funcBody = "BEGIN " ++ concatMap snd deletes ++ "RETURN NEW;END;"
addFunction = CreateOrReplaceFunction $ "CREATE OR REPLACE FUNCTION " ++ withSchema funcName ++ "() RETURNS trigger AS $$" ++ funcBody ++ "$$ LANGUAGE plpgsql"
funcMig = case func of
Nothing | null deletes -> []
Nothing -> [addFunction]
Just (_, Just (DbOther (OtherTypeDef [Left "trigger"])), body) ->
if null deletes -- remove old trigger if a datatype earlier had fields of ephemeral types
then [DropFunction funcName]
else
if body == funcBody
then []
else -- this can happen when an ephemeral field was added or removed.
[DropFunction funcName, addFunction]
_ -> [] -- ignore same name functions which don't return a trigger.
trigBody = "EXECUTE PROCEDURE " ++ withSchema funcName ++ "()"
-- starting from version 11 postgresql returns EXECUTE FUNCTION
trigBody11 = "EXECUTE FUNCTION " ++ withSchema funcName ++ "()"
addTrigger = AddTriggerOnDelete trigName tName trigBody
(trigExisted, trigMig) = case trig of
Nothing | null deletes -> (False, [])
Nothing -> (False, [addTrigger])
Just body ->
( True,
if null deletes -- remove old trigger if a datatype earlier had fields of ephemeral types
then [DropTrigger trigName tName]
else
if body == trigBody || body == trigBody11
then []
else -- this can happen when an ephemeral field was added or removed.
[DropTrigger trigName tName, addTrigger]
)
pure (trigExisted, funcMig ++ trigMig)
-- | Table name and a list of field names and according delete statements
-- assume that this function is called only for ephemeral fields
migTriggerOnUpdate :: QualifiedName -> [(String, String)] -> Action Postgresql [(Bool, [AlterDB])]
migTriggerOnUpdate tName dels = forM dels $ \(fieldName, del) -> do
let funcName = second (\name -> name ++ delim : fieldName) tName
let trigName = second (\name -> name ++ delim : fieldName) tName
func <- analyzeFunction funcName
trig <- analyzeTrigger trigName
let funcBody = "BEGIN " ++ del ++ "RETURN NEW;END;"
addFunction = CreateOrReplaceFunction $ "CREATE OR REPLACE FUNCTION " ++ withSchema funcName ++ "() RETURNS trigger AS $$" ++ funcBody ++ "$$ LANGUAGE plpgsql"
funcMig = case func of
Nothing -> [addFunction]
Just (_, Just (DbOther (OtherTypeDef [Left "trigger"])), body) ->
if body == funcBody
then []
else -- this can happen when an ephemeral field was added or removed.
[DropFunction funcName, addFunction]
_ -> []
trigBody = "EXECUTE PROCEDURE " ++ withSchema funcName ++ "()"
-- starting from version 11 postgresql returns EXECUTE FUNCTION
trigBody11 = "EXECUTE FUNCTION " ++ withSchema funcName ++ "()"
addTrigger = AddTriggerOnUpdate trigName tName (Just fieldName) trigBody
(trigExisted, trigMig) = case trig of
Nothing -> (False, [addTrigger])
Just body ->
( True,
if body == trigBody || body == trigBody11
then []
else -- this can happen when an ephemeral field was added or removed.
[DropTrigger trigName tName, addTrigger]
)
pure (trigExisted, funcMig ++ trigMig)
analyzeTable' :: QualifiedName -> Action Postgresql (Maybe TableInfo)
analyzeTable' name = do
table <- queryRaw' "SELECT * FROM information_schema.tables WHERE table_schema = coalesce(?, current_schema()) AND table_name = ?" (toPurePersistValues name []) >>= firstRow
case table of
Just _ -> do
let colQuery =
"SELECT c.column_name, c.is_nullable, c.udt_name, c.column_default, c.character_maximum_length, c.numeric_precision, c.numeric_scale, c.datetime_precision, c.interval_type, a.attndims AS array_dims, te.typname AS array_elem\
\ FROM pg_catalog.pg_attribute a\
\ INNER JOIN pg_catalog.pg_class cl ON cl.oid = a.attrelid\
\ INNER JOIN pg_catalog.pg_namespace n ON n.oid = cl.relnamespace\
\ INNER JOIN information_schema.columns c ON c.column_name = a.attname AND c.table_name = cl.relname AND c.table_schema = n.nspname\
\ INNER JOIN pg_catalog.pg_type t ON t.oid = a.atttypid\
\ LEFT JOIN pg_catalog.pg_type te ON te.oid = t.typelem\
\ WHERE c.table_schema = coalesce(?, current_schema()) AND c.table_name=?\
\ ORDER BY c.ordinal_position"
cols <- queryRaw' colQuery (toPurePersistValues name []) >>= mapStream (pure . getColumn . fst . fromPurePersistValues) >>= streamToList
let constraintQuery = "SELECT u.constraint_name, u.column_name FROM information_schema.table_constraints tc INNER JOIN information_schema.constraint_column_usage u ON tc.constraint_catalog=u.constraint_catalog AND tc.constraint_schema=u.constraint_schema AND tc.constraint_name=u.constraint_name WHERE tc.constraint_type=? AND tc.table_schema=coalesce(?,current_schema()) AND u.table_name=? ORDER BY u.constraint_name, u.column_name"
uniqConstraints <- queryRaw' constraintQuery (toPurePersistValues ("UNIQUE" :: String, name) []) >>= mapStream (pure . fst . fromPurePersistValues) >>= streamToList
uniqPrimary <- queryRaw' constraintQuery (toPurePersistValues ("PRIMARY KEY" :: String, name) []) >>= mapStream (pure . fst . fromPurePersistValues) >>= streamToList
-- indexes with system columns like oid are omitted
let indexQuery =
"WITH indexes as (\
\SELECT ic.oid, ic.relname,\
\ ta.attnum, ta.attname, pg_get_indexdef(i.indexrelid, ia.attnum, true) as expr\
\ FROM pg_catalog.pg_index i\
\ INNER JOIN pg_catalog.pg_class ic ON ic.oid = i.indexrelid\
\ INNER JOIN pg_catalog.pg_class tc ON i.indrelid = tc.oid\
\ INNER JOIN pg_catalog.pg_attribute ia ON ia.attrelid=ic.oid\
\ LEFT JOIN pg_catalog.pg_attribute ta ON ta.attrelid=tc.oid AND ta.attnum = i.indkey[ia.attnum-1] AND NOT ta.attisdropped\
\ INNER JOIN pg_namespace sch ON sch.oid = tc.relnamespace\
\ WHERE sch.nspname = coalesce(?, current_schema())\
\ AND tc.relname = ?\
\ AND ic.oid NOT IN (SELECT conindid FROM pg_catalog.pg_constraint)\
\ AND NOT i.indisprimary\
\ AND i.indisunique\
\ ORDER BY ic.relname, ia.attnum)\
\SELECT i.relname, i.attname, i.expr\
\ FROM indexes i\
\ INNER JOIN (SELECT oid FROM indexes\
\ GROUP BY oid\
\ HAVING every(attnum > 0 OR attnum IS NULL)) non_system ON i.oid = non_system.oid"
uniqIndexes <- queryRaw' indexQuery (toPurePersistValues name []) >>= mapStream (pure . fst . fromPurePersistValues) >>= streamToList
let mkUniqs typ = map (\us -> UniqueDef (fst $ head us) typ (map snd us)) . groupBy ((==) `on` fst)
isAutoincremented = case filter (\c -> colName c `elem` map snd uniqPrimary) cols of
[c] -> colType c `elem` [DbInt32, DbInt64] && maybe False ("nextval" `isPrefixOf`) (colDefault c)
_ -> False
let uniqs =
mkUniqs UniqueConstraint (map (second Left) uniqConstraints)
++ mkUniqs UniqueIndex (map (second $ \(col, expr) -> maybe (Right expr) Left col) uniqIndexes)
++ mkUniqs (UniquePrimary isAutoincremented) (map (second Left) uniqPrimary)
references <- analyzeTableReferences name
pure $ Just $ TableInfo cols uniqs references
Nothing -> pure Nothing
getColumn :: ((String, String, String, Maybe String), (Maybe Int, Maybe Int, Maybe Int, Maybe Int, Maybe String), (Int, Maybe String)) -> Column
getColumn ((column_name, is_nullable, udt_name, d), modifiers, arr_info) = Column column_name (is_nullable == "YES") t d
where
t = readSqlType udt_name modifiers arr_info
analyzeTableReferences :: QualifiedName -> Action Postgresql [(Maybe String, Reference)]
analyzeTableReferences tName = do
let sql =
"SELECT c.conname, sch_parent.nspname, cl_parent.relname, c. confdeltype, c.confupdtype, a_child.attname AS child, a_parent.attname AS parent FROM\
\ (SELECT r.conrelid, r.confrelid, unnest(r.conkey) AS conkey, unnest(r.confkey) AS confkey, r.conname, r.confupdtype, r.confdeltype\
\ FROM pg_catalog.pg_constraint r WHERE r.contype = 'f'\
\ ) AS c\
\ INNER JOIN pg_attribute a_parent ON a_parent.attnum = c.confkey AND a_parent.attrelid = c.confrelid\
\ INNER JOIN pg_class cl_parent ON cl_parent.oid = c.confrelid\
\ INNER JOIN pg_namespace sch_parent ON sch_parent.oid = cl_parent.relnamespace\
\ INNER JOIN pg_attribute a_child ON a_child.attnum = c.conkey AND a_child.attrelid = c.conrelid\
\ INNER JOIN pg_class cl_child ON cl_child.oid = c.conrelid\
\ INNER JOIN pg_namespace sch_child ON sch_child.oid = cl_child.relnamespace\
\ WHERE sch_child.nspname = coalesce(?, current_schema()) AND cl_child.relname = ?\
\ ORDER BY c.conname"
x <- queryRaw' sql (toPurePersistValues tName []) >>= mapStream (pure . fst . fromPurePersistValues) >>= streamToList
-- (refName, ((parentTableSchema, parentTable, onDelete, onUpdate), (childColumn, parentColumn)))
let mkReference xs = (Just refName, Reference parentTable pairs (mkAction onDelete) (mkAction onUpdate))
where
pairs = map (snd . snd) xs
(refName, ((parentTable, onDelete, onUpdate), _)) = head xs
mkAction c = Just $ case c of
"a" -> NoAction
"r" -> Restrict
"c" -> Cascade
"n" -> SetNull
"d" -> SetDefault
_ -> error $ "unknown reference action type: " ++ c
references = map mkReference $ groupBy ((==) `on` fst) x
pure references
showAlterDb :: AlterDB -> SingleMigration
showAlterDb (AddTable s) = Right [(False, defaultPriority, s)]
showAlterDb (AlterTable t _ _ _ alts) = Right $ concatMap (showAlterTable $ withSchema t) alts
showAlterDb (DropTrigger trigName tName) = Right [(False, triggerPriority, "DROP TRIGGER " ++ withSchema trigName ++ " ON " ++ withSchema tName)]
showAlterDb (AddTriggerOnDelete trigName tName body) = Right [(False, triggerPriority, "CREATE TRIGGER " ++ withSchema trigName ++ " AFTER DELETE ON " ++ withSchema tName ++ " FOR EACH ROW " ++ body)]
showAlterDb (AddTriggerOnUpdate trigName tName fName body) = Right [(False, triggerPriority, "CREATE TRIGGER " ++ withSchema trigName ++ " AFTER UPDATE OF " ++ fName' ++ " ON " ++ withSchema tName ++ " FOR EACH ROW " ++ body)]
where
fName' = maybe (error $ "showAlterDb: AddTriggerOnUpdate does not have fieldName for trigger " ++ show trigName) escape fName
showAlterDb (CreateOrReplaceFunction s) = Right [(False, functionPriority, s)]
showAlterDb (DropFunction funcName) = Right [(False, functionPriority, "DROP FUNCTION " ++ withSchema funcName ++ "()")]
showAlterDb (CreateSchema sch ifNotExists) = Right [(False, schemaPriority, "CREATE SCHEMA " ++ ifNotExists' ++ escape sch)]
where
ifNotExists' = if ifNotExists then "IF NOT EXISTS " else ""
showAlterTable :: String -> AlterTable -> [(Bool, Int, String)]
showAlterTable table (AddColumn col) =
[ ( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" ADD COLUMN ",
showColumn col
]
)
]
showAlterTable table (DropColumn name) =
[ ( True,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" DROP COLUMN ",
escape name
]
)
]
showAlterTable table (AlterColumn col alts) = map (showAlterColumn table $ colName col) alts
showAlterTable table (AddUnique (UniqueDef uName UniqueConstraint cols)) =
[ ( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" ADD",
maybe "" ((" CONSTRAINT " ++) . escape) uName,
" UNIQUE(",
intercalate "," $ map (either escape id) cols,
")"
]
)
]
showAlterTable table (AddUnique (UniqueDef uName UniqueIndex cols)) =
[ ( False,
defaultPriority,
concat
[ "CREATE UNIQUE INDEX ",
maybe "" escape uName,
" ON ",
table,
"(",
intercalate "," $ map (either escape id) cols,
")"
]
)
]
showAlterTable table (AddUnique (UniqueDef uName (UniquePrimary _) cols)) =
[ ( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" ADD",
maybe "" ((" CONSTRAINT " ++) . escape) uName,
" PRIMARY KEY(",
intercalate "," $ map (either escape id) cols,
")"
]
)
]
showAlterTable table (DropConstraint uName) =
[ ( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" DROP CONSTRAINT ",
escape uName
]
)
]
showAlterTable _ (DropIndex uName) =
[ ( False,
defaultPriority,
"DROP INDEX " ++ escape uName
)
]
showAlterTable table (AddReference (Reference tName columns onDelete onUpdate)) =
[ ( False,
referencePriority,
concat
[ "ALTER TABLE ",
table,
" ADD FOREIGN KEY(",
ourKey,
") REFERENCES ",
withSchema tName,
"(",
foreignKey,
")",
maybe "" ((" ON DELETE " ++) . showReferenceAction) onDelete,
maybe "" ((" ON UPDATE " ++) . showReferenceAction) onUpdate
]
)
]
where
(ourKey, foreignKey) = f *** f $ unzip columns
f = intercalate ", " . map escape
showAlterTable table (DropReference name) =
[ ( False,
defaultPriority,
"ALTER TABLE " ++ table ++ " DROP CONSTRAINT " ++ name
)
]
showAlterColumn :: String -> String -> AlterColumn -> (Bool, Int, String)
showAlterColumn table n (Type t) =
( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" ALTER COLUMN ",
escape n,
" TYPE ",
showSqlType t
]
)
showAlterColumn table n IsNull =
( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" ALTER COLUMN ",
escape n,
" DROP NOT NULL"
]
)
showAlterColumn table n NotNull =
( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" ALTER COLUMN ",
escape n,
" SET NOT NULL"
]
)
showAlterColumn table n (Default s) =
( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" ALTER COLUMN ",
escape n,
" SET DEFAULT ",
s
]
)
showAlterColumn table n NoDefault =
( False,
defaultPriority,
concat
[ "ALTER TABLE ",
table,
" ALTER COLUMN ",
escape n,
" DROP DEFAULT"
]
)
showAlterColumn table n (UpdateValue s) =
( False,
defaultPriority,
concat
[ "UPDATE ",
table,
" SET ",
escape n,
"=",
s,
" WHERE ",
escape n,
" IS NULL"
]
)
-- | udt_name, character_maximum_length, numeric_precision, numeric_scale, datetime_precision, interval_type
readSqlType :: String -> (Maybe Int, Maybe Int, Maybe Int, Maybe Int, Maybe String) -> (Int, Maybe String) -> DbTypePrimitive
readSqlType typ (character_maximum_length, numeric_precision, numeric_scale, datetime_precision, _) (array_ndims, array_elem) =
case typ of
"int4" -> DbInt32
"int8" -> DbInt64
"varchar" -> maybe DbString (dbOther . ("varchar" ++) . wrap . show) character_maximum_length
"numeric" -> dbOther $ "numeric" ++ maybe "" wrap attrs
where
attrs = liftM2 (\a b -> if b == 0 then show a else show a ++ ", " ++ show b) numeric_precision numeric_scale
"date" -> DbDay
"bool" -> DbBool
"time" -> mkDate DbTime "time"
"timestamp" -> mkDate DbDayTime "timestamp"
"timestamptz" -> mkDate DbDayTimeZoned "timestamptz"
"float4" -> DbReal
"float8" -> DbReal
"bytea" -> DbBlob
_ | array_ndims > 0 -> dbOther $ arr ++ concat (replicate array_ndims "[]")
where
arr = fromMaybe (error "readSqlType: array with elem type Nothing") array_elem
a -> dbOther a
where
dbOther t = DbOther $ OtherTypeDef [Left t]
wrap x = "(" ++ x ++ ")"
mkDate t name = maybe t (dbOther . (name ++) . wrap . show) datetime_precision'
defDateTimePrec = 6
datetime_precision' = datetime_precision >>= \p -> if p == defDateTimePrec then Nothing else Just p
showSqlType :: DbTypePrimitive -> String
showSqlType t = case t of
DbString -> "VARCHAR"
DbInt32 -> "INT4"
DbInt64 -> "INT8"
DbReal -> "DOUBLE PRECISION"
DbBool -> "BOOLEAN"
DbDay -> "DATE"
DbTime -> "TIME"
DbDayTime -> "TIMESTAMP"
DbDayTimeZoned -> "TIMESTAMP WITH TIME ZONE"
DbBlob -> "BYTEA"
DbOther (OtherTypeDef ts) -> concatMap (either id showSqlType) ts
compareUniqs :: UniqueDefInfo -> UniqueDefInfo -> Bool
compareUniqs (UniqueDef _ (UniquePrimary _) cols1) (UniqueDef _ (UniquePrimary _) cols2) = haveSameElems (==) cols1 cols2
compareUniqs (UniqueDef name1 type1 cols1) (UniqueDef name2 type2 cols2) = (Just False /= liftM2 (==) name1 name2) && type1 == type2 && haveSameElems (==) cols1 cols2
compareRefs :: String -> (Maybe String, Reference) -> (Maybe String, Reference) -> Bool
compareRefs currentSchema (_, Reference (sch1, tbl1) pairs1 onDel1 onUpd1) (_, Reference (sch2, tbl2) pairs2 onDel2 onUpd2) =
fromMaybe currentSchema sch1 == fromMaybe currentSchema sch2
&& unescape tbl1 == unescape tbl2
&& haveSameElems (==) pairs1 pairs2
&& fromMaybe NoAction onDel1 == fromMaybe NoAction onDel2
&& fromMaybe NoAction onUpd1 == fromMaybe NoAction onUpd2
where
unescape name = if head name == '"' && last name == '"' then tail $ init name else name
compareTypes :: DbTypePrimitive -> DbTypePrimitive -> Bool
compareTypes type1 type2 = f type1 == f type2
where
f = map toUpper . showSqlType
compareDefaults :: String -> String -> Bool
compareDefaults def1 def2 = Just def2 `elem` [Just def1, stripType def1, stripType def1 >>= stripParens]
where
stripType = fmap reverse . stripPrefix "::" . dropWhile (\c -> isAlphaNum c || isSpace c) . reverse
stripParens = stripPrefix "(" >=> fmap reverse . stripPrefix ")" . reverse
defaultPriority, schemaPriority, referencePriority, functionPriority, triggerPriority :: Int
defaultPriority = 1
schemaPriority = 0
referencePriority = 2
functionPriority = 3
triggerPriority = 4
mainTableId :: String
mainTableId = "id"
--- MAIN
-- It is used to escape table names and columns, which can include only symbols allowed in Haskell datatypes and '$' delimiter. We need it mostly to support names that coincide with SQL keywords
escape :: String -> String
escape s = '\"' : s ++ "\""
getStatement :: Utf8 -> PG.Query
getStatement sql = PG.Query $ fromUtf8 sql
queryRaw' :: Utf8 -> [PersistValue] -> Action Postgresql (RowStream [PersistValue])
queryRaw' query vals = do
-- $logDebugS "SQL" $ fromString $ show (fromUtf8 query) ++ " " ++ show vals
Postgresql conn <- ask
let open = do
rawquery <- PG.formatQuery conn (getStatement query) (map P vals)
-- Take raw connection
(ret, rowRef, rowCount, getters) <- PG.withConnection conn $ \rawconn -> do
-- Execute query
mret <- LibPQ.exec rawconn rawquery
case mret of
Nothing -> do
merr <- LibPQ.errorMessage rawconn
fail $ case merr of
Nothing -> "Postgresql.queryRaw': unknown error"
Just e -> "Postgresql.queryRaw': " ++ unpack e
Just ret -> do
-- Check result status
status <- LibPQ.resultStatus ret
case status of
LibPQ.TuplesOk -> pure ()
_ -> do
msg <- LibPQ.resStatus status
merr <- LibPQ.errorMessage rawconn
fail $
"Postgresql.queryRaw': bad result status "
++ show status
++ " ("
++ show msg
++ ")"
++ maybe "" ((". Error message: " ++) . unpack) merr
-- Get number and type of columns
cols <- LibPQ.nfields ret
getters <- forM [0 .. cols -1] $ \col -> do
oid <- LibPQ.ftype ret col
pure $ getGetter oid $ PG.Field ret col oid
-- Ready to go!
rowRef <- newIORef (LibPQ.Row 0)
rowCount <- LibPQ.ntuples ret
pure (ret, rowRef, rowCount, getters)
pure $ do
row <- atomicModifyIORef rowRef (\r -> (r + 1, r))
if row == rowCount
then pure Nothing
else fmap Just $
forM (zip getters [0 ..]) $ \(getter, col) -> do
mbs <- LibPQ.getvalue' ret row col
case mbs of
Nothing -> pure PersistNull
Just bs -> do
ok <- PGFF.runConversion (getter mbs) conn
bs `seq` case ok of
Errors (exc : _) -> throw exc
Errors [] -> error "Got an Errors, but no exceptions"
Ok v -> pure v
pure $ mkAcquire open (const $ pure ())
-- | Avoid orphan instances.
newtype P = P PersistValue
instance PGTF.ToField P where
toField (P (PersistString t)) = PGTF.toField t
toField (P (PersistText t)) = PGTF.toField t
toField (P (PersistByteString bs)) = PGTF.toField (PG.Binary bs)
toField (P (PersistInt64 i)) = PGTF.toField i
toField (P (PersistDouble d)) = PGTF.toField d
toField (P (PersistBool b)) = PGTF.toField b
toField (P (PersistDay d)) = PGTF.toField d
toField (P (PersistTimeOfDay t)) = PGTF.toField t
toField (P (PersistUTCTime t)) = PGTF.toField t
toField (P (PersistZonedTime (ZT t))) = PGTF.toField t
toField (P PersistNull) = PGTF.toField PG.Null
toField (P (PersistCustom _ _)) = error "toField: unexpected PersistCustom"
type Getter a = PGFF.FieldParser a
convertPV :: PGFF.FromField a => (a -> b) -> Getter b
convertPV f = (fmap f .) . PGFF.fromField
getGetter :: PG.Oid -> Getter PersistValue
getGetter (PG.Oid oid) = case oid of
16 -> convertPV PersistBool
17 -> convertPV (PersistByteString . unBinary)
18 -> convertPV PersistText
19 -> convertPV PersistText
20 -> convertPV PersistInt64
21 -> convertPV PersistInt64
23 -> convertPV PersistInt64
25 -> convertPV PersistText
142 -> convertPV PersistText
700 -> convertPV PersistDouble
701 -> convertPV PersistDouble
702 -> convertPV PersistUTCTime
703 -> convertPV PersistUTCTime
1042 -> convertPV PersistText
1043 -> convertPV PersistText
1082 -> convertPV PersistDay
1083 -> convertPV PersistTimeOfDay
1114 -> convertPV (PersistUTCTime . localTimeToUTC utc)
1184 -> convertPV (PersistZonedTime . ZT)
1560 -> convertPV PersistInt64
1562 -> convertPV PersistInt64
1700 -> convertPV (PersistDouble . fromRational)
2278 -> \_ _ -> pure PersistNull
_ -> \f dat -> fmap PersistByteString $ case dat of
Nothing -> PGFF.returnError PGFF.UnexpectedNull f ""
Just str -> pure $ copy str
unBinary :: PG.Binary a -> a
unBinary (PG.Binary x) = x
proxy :: proxy Postgresql
proxy = error "proxy Postgresql"
withSchema :: QualifiedName -> String
withSchema (sch, name) = maybe "" (\x -> escape x ++ ".") sch ++ escape name
-- | Put explicit type for expression. It is useful for values which are defaulted to a wrong type.
-- For example, a literal Int from a 64bit machine can be defaulted to a 32bit int by Postgresql.
-- Also a value entered as an external string (geometry, arrays and other complex types have this representation) may need an explicit type.
explicitType :: (Expression Postgresql r a, PersistField a) => a -> Expr Postgresql r a
explicitType a = castType a t
where
t = case dbType proxy a of
DbTypePrimitive t' _ _ _ -> showSqlType t'
_ -> error "explicitType: type is not primitive"
-- | Casts expression to a type. @castType value \"INT\"@ results in @value::INT@.
castType :: (Expression Postgresql r a, PersistField a) => a -> String -> Expr Postgresql r a
castType a t = mkExpr $ Snippet $ \conf _ -> ["(" <> renderExpr conf (toExpr a) <> ")::" <> fromString t]
-- | Distinct only on certain fields or expressions. For example, @select $ CondEmpty `distinctOn` (lower EmailField, IpField)@.
distinctOn :: (db ~ Postgresql, HasSelectOptions a db r, HasDistinct a ~ HFalse, Projection' p db r p') => a -> p -> SelectOptions db r (HasLimit a) (HasOffset a) (HasOrder a) HTrue
distinctOn opts p = opts' {dbSpecificOptions = ("DISTINCT_ON", clause) : dbSpecificOptions opts'}
where
opts' = getSelectOptions opts
clause = Snippet $ \conf _ -> [commasJoin $ concatMap (renderExprExtended conf 0) $ projectionExprs p []]
preColumns :: HasSelectOptions opts Postgresql r => opts -> RenderS Postgresql r
preColumns opts = clause
where
clause = apply "DISTINCT_ON" (\t -> "DISTINCT ON (" <> t <> ")")
apply k f = case lookup k opts' of
Nothing -> mempty
Just (Snippet snippet) -> f $ head $ snippet renderConfig 0
opts' = dbSpecificOptions $ getSelectOptions opts