{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE ViewPatterns #-}
-- | A postgresql backend for persistent.
module Database.Persist.Postgresql
( withPostgresqlPool
, withPostgresqlPoolWithVersion
, withPostgresqlConn
, withPostgresqlConnWithVersion
, withPostgresqlPoolWithConf
, createPostgresqlPool
, createPostgresqlPoolModified
, createPostgresqlPoolModifiedWithVersion
, createPostgresqlPoolWithConf
, module Database.Persist.Sql
, ConnectionString
, HandleUpdateCollision
, copyField
, copyUnlessNull
, copyUnlessEmpty
, copyUnlessEq
, excludeNotEqualToOriginal
, PostgresConf (..)
, PgInterval (..)
, upsertWhere
, upsertManyWhere
, openSimpleConn
, openSimpleConnWithVersion
, tableName
, fieldName
, mockMigration
, migrateEnableExtension
, PostgresConfHooks(..)
, defaultPostgresConfHooks
) where
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.Transaction as PG
import qualified Database.PostgreSQL.Simple.TypeInfo.Static as PS
import qualified Database.PostgreSQL.Simple.Types as PG
import Data.Proxy (Proxy(..))
import qualified Data.List.NonEmpty as NEL
import Control.Arrow
import Control.Exception (Exception, throw, throwIO)
import Control.Monad
import Control.Monad.Except
import Control.Monad.IO.Unlift (MonadIO(..), MonadUnliftIO)
import Control.Monad.Logger (MonadLoggerIO, runNoLoggingT)
import Control.Monad.Trans.Reader (ReaderT(..), asks, runReaderT)
import Control.Monad.Trans.Writer (WriterT(..), runWriterT)
import qualified Blaze.ByteString.Builder.Char8 as BBB
import Data.Acquire (Acquire, mkAcquire, with)
import Data.Aeson
import Data.Aeson.Types (modifyFailure)
import qualified Data.Attoparsec.ByteString.Char8 as P
import qualified Data.Attoparsec.Text as AT
import Data.Bits ((.&.))
import Data.ByteString (ByteString)
import qualified Data.ByteString.Builder as BB
import qualified Data.ByteString.Char8 as B8
import Data.Char (ord)
import Data.Conduit
import qualified Data.Conduit.List as CL
import Data.Data (Data, Typeable)
import Data.Either (partitionEithers)
import Data.Fixed (Fixed(..), Pico)
import Data.Function (on)
import Data.IORef
import Data.Int (Int64)
import qualified Data.IntMap as I
import Data.List (find, foldl', groupBy, sort)
import qualified Data.List as List
import Data.List.NonEmpty (NonEmpty)
import qualified Data.List.NonEmpty as NEL
import qualified Data.Map as Map
import Data.Maybe
import Data.Monoid ((<>))
import qualified Data.Monoid as Monoid
import Data.Pool (Pool)
import Data.String.Conversions.Monomorphic (toStrictByteString)
import Data.Text (Text)
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import qualified Data.Text.IO as T
import Data.Text.Read (rational)
import Data.Time (NominalDiffTime, localTimeToUTC, utc)
import System.Environment (getEnvironment)
import Database.Persist.Sql
import Database.Persist.SqlBackend
import qualified Database.Persist.Sql.Util as Util
-- | A @libpq@ connection string. A simple example of connection
-- string would be @\"host=localhost port=5432 user=test
-- dbname=test password=test\"@. Please read libpq's
-- documentation at
-- <https://www.postgresql.org/docs/current/static/libpq-connect.html>
-- for more details on how to create such strings.
type ConnectionString = ByteString
-- | PostgresServerVersionError exception. This is thrown when persistent
-- is unable to find the version of the postgreSQL server.
data PostgresServerVersionError = PostgresServerVersionError String
instance Show PostgresServerVersionError where
show (PostgresServerVersionError uniqueMsg) =
"Unexpected PostgreSQL server version, got " <> uniqueMsg
instance Exception PostgresServerVersionError
-- | Create a PostgreSQL connection pool and run the given action. The pool is
-- properly released after the action finishes using it. Note that you should
-- not use the given 'ConnectionPool' outside the action since it may already
-- have been released.
-- The provided action should use 'runSqlConn' and *not* 'runReaderT' because
-- the former brackets the database action with transaction begin/commit.
withPostgresqlPool :: (MonadLoggerIO m, MonadUnliftIO m)
=> ConnectionString
-- ^ Connection string to the database.
-> Int
-- ^ Number of connections to be kept open in
-- the pool.
-> (Pool SqlBackend -> m a)
-- ^ Action to be executed that uses the
-- connection pool.
-> m a
withPostgresqlPool ci = withPostgresqlPoolWithVersion getServerVersion ci
-- | Same as 'withPostgresPool', but takes a callback for obtaining
-- the server version (to work around an Amazon Redshift bug).
--
-- @since 2.6.2
withPostgresqlPoolWithVersion :: (MonadUnliftIO m, MonadLoggerIO m)
=> (PG.Connection -> IO (Maybe Double))
-- ^ Action to perform to get the server version.
-> ConnectionString
-- ^ Connection string to the database.
-> Int
-- ^ Number of connections to be kept open in
-- the pool.
-> (Pool SqlBackend -> m a)
-- ^ Action to be executed that uses the
-- connection pool.
-> m a
withPostgresqlPoolWithVersion getVerDouble ci = do
let getVer = oldGetVersionToNew getVerDouble
withSqlPool $ open' (const $ return ()) getVer ci
-- | Same as 'withPostgresqlPool', but can be configured with 'PostgresConf' and 'PostgresConfHooks'.
--
-- @since 2.11.0.0
withPostgresqlPoolWithConf :: (MonadUnliftIO m, MonadLoggerIO m)
=> PostgresConf -- ^ Configuration for connecting to Postgres
-> PostgresConfHooks -- ^ Record of callback functions
-> (Pool SqlBackend -> m a)
-- ^ Action to be executed that uses the
-- connection pool.
-> m a
withPostgresqlPoolWithConf conf hooks = do
let getVer = pgConfHooksGetServerVersion hooks
modConn = pgConfHooksAfterCreate hooks
let logFuncToBackend = open' modConn getVer (pgConnStr conf)
withSqlPoolWithConfig logFuncToBackend (postgresConfToConnectionPoolConfig conf)
-- | Create a PostgreSQL connection pool. Note that it's your
-- responsibility to properly close the connection pool when
-- unneeded. Use 'withPostgresqlPool' for an automatic resource
-- control.
createPostgresqlPool :: (MonadUnliftIO m, MonadLoggerIO m)
=> ConnectionString
-- ^ Connection string to the database.
-> Int
-- ^ Number of connections to be kept open
-- in the pool.
-> m (Pool SqlBackend)
createPostgresqlPool = createPostgresqlPoolModified (const $ return ())
-- | Same as 'createPostgresqlPool', but additionally takes a callback function
-- for some connection-specific tweaking to be performed after connection
-- creation. This could be used, for example, to change the schema. For more
-- information, see:
--
-- <https://groups.google.com/d/msg/yesodweb/qUXrEN_swEo/O0pFwqwQIdcJ>
--
-- @since 2.1.3
createPostgresqlPoolModified
:: (MonadUnliftIO m, MonadLoggerIO m)
=> (PG.Connection -> IO ()) -- ^ Action to perform after connection is created.
-> ConnectionString -- ^ Connection string to the database.
-> Int -- ^ Number of connections to be kept open in the pool.
-> m (Pool SqlBackend)
createPostgresqlPoolModified = createPostgresqlPoolModifiedWithVersion getServerVersion
-- | Same as other similarly-named functions in this module, but takes callbacks for obtaining
-- the server version (to work around an Amazon Redshift bug) and connection-specific tweaking
-- (to change the schema).
--
-- @since 2.6.2
createPostgresqlPoolModifiedWithVersion
:: (MonadUnliftIO m, MonadLoggerIO m)
=> (PG.Connection -> IO (Maybe Double)) -- ^ Action to perform to get the server version.
-> (PG.Connection -> IO ()) -- ^ Action to perform after connection is created.
-> ConnectionString -- ^ Connection string to the database.
-> Int -- ^ Number of connections to be kept open in the pool.
-> m (Pool SqlBackend)
createPostgresqlPoolModifiedWithVersion getVerDouble modConn ci = do
let getVer = oldGetVersionToNew getVerDouble
createSqlPool $ open' modConn getVer ci
-- | Same as 'createPostgresqlPool', but can be configured with 'PostgresConf' and 'PostgresConfHooks'.
--
-- @since 2.11.0.0
createPostgresqlPoolWithConf
:: (MonadUnliftIO m, MonadLoggerIO m)
=> PostgresConf -- ^ Configuration for connecting to Postgres
-> PostgresConfHooks -- ^ Record of callback functions
-> m (Pool SqlBackend)
createPostgresqlPoolWithConf conf hooks = do
let getVer = pgConfHooksGetServerVersion hooks
modConn = pgConfHooksAfterCreate hooks
createSqlPoolWithConfig (open' modConn getVer (pgConnStr conf)) (postgresConfToConnectionPoolConfig conf)
postgresConfToConnectionPoolConfig :: PostgresConf -> ConnectionPoolConfig
postgresConfToConnectionPoolConfig conf =
ConnectionPoolConfig
{ connectionPoolConfigStripes = pgPoolStripes conf
, connectionPoolConfigIdleTimeout = fromInteger $ pgPoolIdleTimeout conf
, connectionPoolConfigSize = pgPoolSize conf
}
-- | Same as 'withPostgresqlPool', but instead of opening a pool
-- of connections, only one connection is opened.
-- The provided action should use 'runSqlConn' and *not* 'runReaderT' because
-- the former brackets the database action with transaction begin/commit.
withPostgresqlConn :: (MonadUnliftIO m, MonadLoggerIO m)
=> ConnectionString -> (SqlBackend -> m a) -> m a
withPostgresqlConn = withPostgresqlConnWithVersion getServerVersion
-- | Same as 'withPostgresqlConn', but takes a callback for obtaining
-- the server version (to work around an Amazon Redshift bug).
--
-- @since 2.6.2
withPostgresqlConnWithVersion :: (MonadUnliftIO m, MonadLoggerIO m)
=> (PG.Connection -> IO (Maybe Double))
-> ConnectionString
-> (SqlBackend -> m a)
-> m a
withPostgresqlConnWithVersion getVerDouble = do
let getVer = oldGetVersionToNew getVerDouble
withSqlConn . open' (const $ return ()) getVer
open'
:: (PG.Connection -> IO ())
-> (PG.Connection -> IO (NonEmpty Word))
-> ConnectionString -> LogFunc -> IO SqlBackend
open' modConn getVer cstr logFunc = do
conn <- PG.connectPostgreSQL cstr
modConn conn
ver <- getVer conn
smap <- newIORef $ Map.empty
return $ createBackend logFunc ver smap conn
-- | Gets the PostgreSQL server version
getServerVersion :: PG.Connection -> IO (Maybe Double)
getServerVersion conn = do
[PG.Only version] <- PG.query_ conn "show server_version";
let version' = rational version
--- λ> rational "9.8.3"
--- Right (9.8,".3")
--- λ> rational "9.8.3.5"
--- Right (9.8,".3.5")
case version' of
Right (a,_) -> return $ Just a
Left err -> throwIO $ PostgresServerVersionError err
getServerVersionNonEmpty :: PG.Connection -> IO (NonEmpty Word)
getServerVersionNonEmpty conn = do
[PG.Only version] <- PG.query_ conn "show server_version";
case AT.parseOnly parseVersion (T.pack version) of
Left err -> throwIO $ PostgresServerVersionError $ "Parse failure on: " <> version <> ". Error: " <> err
Right versionComponents -> case NEL.nonEmpty versionComponents of
Nothing -> throwIO $ PostgresServerVersionError $ "Empty Postgres version string: " <> version
Just neVersion -> pure neVersion
where
-- Partially copied from the `versions` package
-- Typically server_version gives e.g. 12.3
-- In Persistent's CI, we get "12.4 (Debian 12.4-1.pgdg100+1)", so we ignore the trailing data.
parseVersion = AT.decimal `AT.sepBy` AT.char '.'
-- | Choose upsert sql generation function based on postgresql version.
-- PostgreSQL version >= 9.5 supports native upsert feature,
-- so depending upon that we have to choose how the sql query is generated.
-- upsertFunction :: Double -> Maybe (EntityDef -> Text -> Text)
upsertFunction :: a -> NonEmpty Word -> Maybe a
upsertFunction f version = if (version >= postgres9dot5)
then Just f
else Nothing
where
postgres9dot5 :: NonEmpty Word
postgres9dot5 = 9 NEL.:| [5]
-- | If the user doesn't supply a Postgres version, we assume this version.
--
-- This is currently below any version-specific features Persistent uses.
minimumPostgresVersion :: NonEmpty Word
minimumPostgresVersion = 9 NEL.:| [4]
oldGetVersionToNew :: (PG.Connection -> IO (Maybe Double)) -> (PG.Connection -> IO (NonEmpty Word))
oldGetVersionToNew oldFn = \conn -> do
mDouble <- oldFn conn
case mDouble of
Nothing -> pure minimumPostgresVersion
Just double -> do
let (major, minor) = properFraction double
pure $ major NEL.:| [floor minor]
-- | Generate a 'SqlBackend' from a 'PG.Connection'.
openSimpleConn :: LogFunc -> PG.Connection -> IO SqlBackend
openSimpleConn = openSimpleConnWithVersion getServerVersion
-- | Generate a 'SqlBackend' from a 'PG.Connection', but takes a callback for
-- obtaining the server version.
--
-- @since 2.9.1
openSimpleConnWithVersion :: (PG.Connection -> IO (Maybe Double)) -> LogFunc -> PG.Connection -> IO SqlBackend
openSimpleConnWithVersion getVerDouble logFunc conn = do
smap <- newIORef $ Map.empty
serverVersion <- oldGetVersionToNew getVerDouble conn
return $ createBackend logFunc serverVersion smap conn
-- | Create the backend given a logging function, server version, mutable statement cell,
-- and connection.
createBackend :: LogFunc -> NonEmpty Word
-> IORef (Map.Map Text Statement) -> PG.Connection -> SqlBackend
createBackend logFunc serverVersion smap conn =
maybe id setConnPutManySql (upsertFunction putManySql serverVersion) $
maybe id setConnUpsertSql (upsertFunction upsertSql' serverVersion) $
setConnInsertManySql insertManySql' $
maybe id setConnRepsertManySql (upsertFunction repsertManySql serverVersion) $
mkSqlBackend MkSqlBackendArgs
{ connPrepare = prepare' conn
, connStmtMap = smap
, connInsertSql = insertSql'
, connClose = PG.close conn
, connMigrateSql = migrate'
, connBegin = \_ mIsolation -> case mIsolation of
Nothing -> PG.begin conn
Just iso -> PG.beginLevel (case iso of
ReadUncommitted -> PG.ReadCommitted -- PG Upgrades uncommitted reads to committed anyways
ReadCommitted -> PG.ReadCommitted
RepeatableRead -> PG.RepeatableRead
Serializable -> PG.Serializable) conn
, connCommit = const $ PG.commit conn
, connRollback = const $ PG.rollback conn
, connEscapeFieldName = escapeF
, connEscapeTableName = escapeE . getEntityDBName
, connEscapeRawName = escape
, connNoLimit = "LIMIT ALL"
, connRDBMS = "postgresql"
, connLimitOffset = decorateSQLWithLimitOffset "LIMIT ALL"
, connLogFunc = logFunc
}
prepare' :: PG.Connection -> Text -> IO Statement
prepare' conn sql = do
let query = PG.Query (T.encodeUtf8 sql)
return Statement
{ stmtFinalize = return ()
, stmtReset = return ()
, stmtExecute = execute' conn query
, stmtQuery = withStmt' conn query
}
insertSql' :: EntityDef -> [PersistValue] -> InsertSqlResult
insertSql' ent vals =
case getEntityId ent of
EntityIdNaturalKey _pdef ->
ISRManyKeys sql vals
EntityIdField field ->
ISRSingle (sql <> " RETURNING " <> escapeF (fieldDB field))
where
(fieldNames, placeholders) = unzip (Util.mkInsertPlaceholders ent escapeF)
sql = T.concat
[ "INSERT INTO "
, escapeE $ getEntityDBName ent
, if null (getEntityFieldsDatabase ent)
then " DEFAULT VALUES"
else T.concat
[ "("
, T.intercalate "," fieldNames
, ") VALUES("
, T.intercalate "," placeholders
, ")"
]
]
upsertSql' :: EntityDef -> NonEmpty (FieldNameHS, FieldNameDB) -> Text -> Text
upsertSql' ent uniqs updateVal =
T.concat
[ "INSERT INTO "
, escapeE (getEntityDBName ent)
, "("
, T.intercalate "," fieldNames
, ") VALUES ("
, T.intercalate "," placeholders
, ") ON CONFLICT ("
, T.intercalate "," $ map (escapeF . snd) (NEL.toList uniqs)
, ") DO UPDATE SET "
, updateVal
, " WHERE "
, wher
, " RETURNING ??"
]
where
(fieldNames, placeholders) = unzip (Util.mkInsertPlaceholders ent escapeF)
wher = T.intercalate " AND " $ map (singleClause . snd) $ NEL.toList uniqs
singleClause :: FieldNameDB -> Text
singleClause field = escapeE (getEntityDBName ent) <> "." <> (escapeF field) <> " =?"
-- | SQL for inserting multiple rows at once and returning their primary keys.
insertManySql' :: EntityDef -> [[PersistValue]] -> InsertSqlResult
insertManySql' ent valss =
ISRSingle sql
where
(fieldNames, placeholders)= unzip (Util.mkInsertPlaceholders ent escapeF)
sql = T.concat
[ "INSERT INTO "
, escapeE (getEntityDBName ent)
, "("
, T.intercalate "," fieldNames
, ") VALUES ("
, T.intercalate "),(" $ replicate (length valss) $ T.intercalate "," placeholders
, ") RETURNING "
, Util.commaSeparated $ NEL.toList $ Util.dbIdColumnsEsc escapeF ent
]
execute' :: PG.Connection -> PG.Query -> [PersistValue] -> IO Int64
execute' conn query vals = PG.execute conn query (map P vals)
withStmt' :: MonadIO m
=> PG.Connection
-> PG.Query
-> [PersistValue]
-> Acquire (ConduitM () [PersistValue] m ())
withStmt' conn query vals =
pull `fmap` mkAcquire openS closeS
where
openS = do
-- Construct raw query
rawquery <- PG.formatQuery conn query (map P vals)
-- Take raw connection
(rt, rr, rc, ids) <- 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.withStmt': unknown error"
Just e -> "Postgresql.withStmt': " ++ B8.unpack e
Just ret -> do
-- Check result status
status <- LibPQ.resultStatus ret
case status of
LibPQ.TuplesOk -> return ()
_ -> PG.throwResultError "Postgresql.withStmt': bad result status " ret status
-- Get number and type of columns
cols <- LibPQ.nfields ret
oids <- forM [0..cols-1] $ \col -> fmap ((,) col) (LibPQ.ftype ret col)
-- Ready to go!
rowRef <- newIORef (LibPQ.Row 0)
rowCount <- LibPQ.ntuples ret
return (ret, rowRef, rowCount, oids)
let getters
= map (\(col, oid) -> getGetter conn oid $ PG.Field rt col oid) ids
return (rt, rr, rc, getters)
closeS (ret, _, _, _) = LibPQ.unsafeFreeResult ret
pull x = do
y <- liftIO $ pullS x
case y of
Nothing -> return ()
Just z -> yield z >> pull x
pullS (ret, rowRef, rowCount, getters) = do
row <- atomicModifyIORef rowRef (\r -> (r+1, r))
if row == rowCount
then return Nothing
else fmap Just $ forM (zip getters [0..]) $ \(getter, col) -> do
mbs <- LibPQ.getvalue' ret row col
case mbs of
Nothing ->
-- getvalue' verified that the value is NULL.
-- However, that does not mean that there are
-- no NULL values inside the value (e.g., if
-- we're dealing with an array of optional values).
return 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 -> return v
-- | Avoid orphan instances.
newtype P = P PersistValue
instance PGTF.ToField P where
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 (PersistRational r)) = PGTF.Plain $
BBB.fromString $
show (fromRational r :: Pico) -- FIXME: Too Ambigous, can not select precision without information about field
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 PersistNull) = PGTF.toField PG.Null
toField (P (PersistList l)) = PGTF.toField $ listToJSON l
toField (P (PersistMap m)) = PGTF.toField $ mapToJSON m
toField (P (PersistLiteral_ DbSpecific s)) = PGTF.toField (Unknown s)
toField (P (PersistLiteral_ Unescaped l)) = PGTF.toField (UnknownLiteral l)
toField (P (PersistLiteral_ Escaped e)) = PGTF.toField (Unknown e)
toField (P (PersistArray a)) = PGTF.toField $ PG.PGArray $ P <$> a
toField (P (PersistObjectId _)) =
error "Refusing to serialize a PersistObjectId to a PostgreSQL value"
-- | Represent Postgres interval using NominalDiffTime
--
-- @since 2.11.0.0
newtype PgInterval = PgInterval { getPgInterval :: NominalDiffTime }
deriving (Eq, Show)
pgIntervalToBs :: PgInterval -> ByteString
pgIntervalToBs = toStrictByteString . show . getPgInterval
instance PGTF.ToField PgInterval where
toField (PgInterval t) = PGTF.toField t
instance PGFF.FromField PgInterval where
fromField f mdata =
if PGFF.typeOid f /= PS.typoid PS.interval
then PGFF.returnError PGFF.Incompatible f ""
else case mdata of
Nothing -> PGFF.returnError PGFF.UnexpectedNull f ""
Just dat -> case P.parseOnly (nominalDiffTime <* P.endOfInput) dat of
Left msg -> PGFF.returnError PGFF.ConversionFailed f msg
Right t -> return $ PgInterval t
where
toPico :: Integer -> Pico
toPico = MkFixed
-- Taken from Database.PostgreSQL.Simple.Time.Internal.Parser
twoDigits :: P.Parser Int
twoDigits = do
a <- P.digit
b <- P.digit
let c2d c = ord c .&. 15
return $! c2d a * 10 + c2d b
-- Taken from Database.PostgreSQL.Simple.Time.Internal.Parser
seconds :: P.Parser Pico
seconds = do
real <- twoDigits
mc <- P.peekChar
case mc of
Just '.' -> do
t <- P.anyChar *> P.takeWhile1 P.isDigit
return $! parsePicos (fromIntegral real) t
_ -> return $! fromIntegral real
where
parsePicos :: Int64 -> B8.ByteString -> Pico
parsePicos a0 t = toPico (fromIntegral (t' * 10^n))
where n = max 0 (12 - B8.length t)
t' = B8.foldl' (\a c -> 10 * a + fromIntegral (ord c .&. 15)) a0
(B8.take 12 t)
parseSign :: P.Parser Bool
parseSign = P.choice [P.char '-' >> return True, return False]
-- Db stores it in [-]HHH:MM:SS.[SSSS]
-- For example, nominalDay is stored as 24:00:00
interval :: P.Parser (Bool, Int, Int, Pico)
interval = do
s <- parseSign
h <- P.decimal <* P.char ':'
m <- twoDigits <* P.char ':'
ss <- seconds
if m < 60 && ss <= 60
then return (s, h, m, ss)
else fail "Invalid interval"
nominalDiffTime :: P.Parser NominalDiffTime
nominalDiffTime = do
(s, h, m, ss) <- interval
let pico = ss + 60 * (fromIntegral m) + 60 * 60 * (fromIntegral (abs h))
return . fromRational . toRational $ if s then (-pico) else pico
fromPersistValueError :: Text -- ^ Haskell type, should match Haskell name exactly, e.g. "Int64"
-> Text -- ^ Database type(s), should appear different from Haskell name, e.g. "integer" or "INT", not "Int".
-> PersistValue -- ^ Incorrect value
-> Text -- ^ Error message
fromPersistValueError haskellType databaseType received = T.concat
[ "Failed to parse Haskell type `"
, haskellType
, "`; expected "
, databaseType
, " from database, but received: "
, T.pack (show received)
, ". Potential solution: Check that your database schema matches your Persistent model definitions."
]
instance PersistField PgInterval where
toPersistValue = PersistLiteralEscaped . pgIntervalToBs
fromPersistValue (PersistLiteral_ DbSpecific bs) =
fromPersistValue (PersistLiteralEscaped bs)
fromPersistValue x@(PersistLiteral_ Escaped bs) =
case P.parseOnly (P.signed P.rational <* P.char 's' <* P.endOfInput) bs of
Left _ -> Left $ fromPersistValueError "PgInterval" "Interval" x
Right i -> Right $ PgInterval i
fromPersistValue x = Left $ fromPersistValueError "PgInterval" "Interval" x
instance PersistFieldSql PgInterval where
sqlType _ = SqlOther "interval"
newtype Unknown = Unknown { unUnknown :: ByteString }
deriving (Eq, Show, Read, Ord)
instance PGFF.FromField Unknown where
fromField f mdata =
case mdata of
Nothing -> PGFF.returnError PGFF.UnexpectedNull f "Database.Persist.Postgresql/PGFF.FromField Unknown"
Just dat -> return (Unknown dat)
instance PGTF.ToField Unknown where
toField (Unknown a) = PGTF.Escape a
newtype UnknownLiteral = UnknownLiteral { unUnknownLiteral :: ByteString }
deriving (Eq, Show, Read, Ord, Typeable)
instance PGFF.FromField UnknownLiteral where
fromField f mdata =
case mdata of
Nothing -> PGFF.returnError PGFF.UnexpectedNull f "Database.Persist.Postgresql/PGFF.FromField UnknownLiteral"
Just dat -> return (UnknownLiteral dat)
instance PGTF.ToField UnknownLiteral where
toField (UnknownLiteral a) = PGTF.Plain $ BB.byteString a
type Getter a = PGFF.FieldParser a
convertPV :: PGFF.FromField a => (a -> b) -> Getter b
convertPV f = (fmap f .) . PGFF.fromField
builtinGetters :: I.IntMap (Getter PersistValue)
builtinGetters = I.fromList
[ (k PS.bool, convertPV PersistBool)
, (k PS.bytea, convertPV (PersistByteString . unBinary))
, (k PS.char, convertPV PersistText)
, (k PS.name, convertPV PersistText)
, (k PS.int8, convertPV PersistInt64)
, (k PS.int2, convertPV PersistInt64)
, (k PS.int4, convertPV PersistInt64)
, (k PS.text, convertPV PersistText)
, (k PS.xml, convertPV (PersistByteString . unUnknown))
, (k PS.float4, convertPV PersistDouble)
, (k PS.float8, convertPV PersistDouble)
, (k PS.money, convertPV PersistRational)
, (k PS.bpchar, convertPV PersistText)
, (k PS.varchar, convertPV PersistText)
, (k PS.date, convertPV PersistDay)
, (k PS.time, convertPV PersistTimeOfDay)
, (k PS.timestamp, convertPV (PersistUTCTime. localTimeToUTC utc))
, (k PS.timestamptz, convertPV PersistUTCTime)
, (k PS.interval, convertPV (PersistLiteralEscaped . pgIntervalToBs))
, (k PS.bit, convertPV PersistInt64)
, (k PS.varbit, convertPV PersistInt64)
, (k PS.numeric, convertPV PersistRational)
, (k PS.void, \_ _ -> return PersistNull)
, (k PS.json, convertPV (PersistByteString . unUnknown))
, (k PS.jsonb, convertPV (PersistByteString . unUnknown))
, (k PS.unknown, convertPV (PersistByteString . unUnknown))
-- Array types: same order as above.
-- The OIDs were taken from pg_type.
, (1000, listOf PersistBool)
, (1001, listOf (PersistByteString . unBinary))
, (1002, listOf PersistText)
, (1003, listOf PersistText)
, (1016, listOf PersistInt64)
, (1005, listOf PersistInt64)
, (1007, listOf PersistInt64)
, (1009, listOf PersistText)
, (143, listOf (PersistByteString . unUnknown))
, (1021, listOf PersistDouble)
, (1022, listOf PersistDouble)
, (1023, listOf PersistUTCTime)
, (1024, listOf PersistUTCTime)
, (791, listOf PersistRational)
, (1014, listOf PersistText)
, (1015, listOf PersistText)
, (1182, listOf PersistDay)
, (1183, listOf PersistTimeOfDay)
, (1115, listOf PersistUTCTime)
, (1185, listOf PersistUTCTime)
, (1187, listOf (PersistLiteralEscaped . pgIntervalToBs))
, (1561, listOf PersistInt64)
, (1563, listOf PersistInt64)
, (1231, listOf PersistRational)
-- no array(void) type
, (2951, listOf (PersistLiteralEscaped . unUnknown))
, (199, listOf (PersistByteString . unUnknown))
, (3807, listOf (PersistByteString . unUnknown))
-- no array(unknown) either
]
where
k (PGFF.typoid -> i) = PG.oid2int i
-- A @listOf f@ will use a @PGArray (Maybe T)@ to convert
-- the values to Haskell-land. The @Maybe@ is important
-- because the usual way of checking NULLs
-- (c.f. withStmt') won't check for NULL inside
-- arrays---or any other compound structure for that matter.
listOf f = convertPV (PersistList . map (nullable f) . PG.fromPGArray)
where nullable = maybe PersistNull
getGetter :: PG.Connection -> PG.Oid -> Getter PersistValue
getGetter _conn oid
= fromMaybe defaultGetter $ I.lookup (PG.oid2int oid) builtinGetters
where defaultGetter = convertPV (PersistLiteralEscaped . unUnknown)
unBinary :: PG.Binary a -> a
unBinary (PG.Binary x) = x
doesTableExist :: (Text -> IO Statement)
-> EntityNameDB
-> IO Bool
doesTableExist getter (EntityNameDB name) = do
stmt <- getter sql
with (stmtQuery stmt vals) (\src -> runConduit $ src .| start)
where
sql = "SELECT COUNT(*) FROM pg_catalog.pg_tables WHERE schemaname != 'pg_catalog'"
<> " AND schemaname != 'information_schema' AND tablename=?"
vals = [PersistText name]
start = await >>= maybe (error "No results when checking doesTableExist") start'
start' [PersistInt64 0] = finish False
start' [PersistInt64 1] = finish True
start' res = error $ "doesTableExist returned unexpected result: " ++ show res
finish x = await >>= maybe (return x) (error "Too many rows returned in doesTableExist")
migrate' :: [EntityDef]
-> (Text -> IO Statement)
-> EntityDef
-> IO (Either [Text] [(Bool, Text)])
migrate' allDefs getter entity = fmap (fmap $ map showAlterDb) $ do
old <- getColumns getter entity newcols'
case partitionEithers old of
([], old'') -> do
exists' <-
if null old
then doesTableExist getter name
else return True
return $ Right $ migrationText exists' old''
(errs, _) -> return $ Left errs
where
name = getEntityDBName entity
(newcols', udefs, fdefs) = postgresMkColumns allDefs entity
migrationText exists' old''
| not exists' =
createText newcols fdefs udspair
| otherwise =
let (acs, ats) =
getAlters allDefs entity (newcols, udspair) old'
acs' = map (AlterColumn name) acs
ats' = map (AlterTable name) ats
in
acs' ++ ats'
where
old' = partitionEithers old''
newcols = filter (not . safeToRemove entity . cName) newcols'
udspair = map udToPair udefs
-- Check for table existence if there are no columns, workaround
-- for https://github.com/yesodweb/persistent/issues/152
createText newcols fdefs_ udspair =
(addTable newcols entity) : uniques ++ references ++ foreignsAlt
where
uniques = flip concatMap udspair $ \(uname, ucols) ->
[AlterTable name $ AddUniqueConstraint uname ucols]
references =
mapMaybe
(\Column { cName, cReference } ->
getAddReference allDefs entity cName =<< cReference
)
newcols
foreignsAlt = mapMaybe (mkForeignAlt entity) fdefs_
mkForeignAlt
:: EntityDef
-> ForeignDef
-> Maybe AlterDB
mkForeignAlt entity fdef = pure $ AlterColumn tableName_ addReference
where
tableName_ = getEntityDBName entity
addReference =
AddReference
(foreignRefTableDBName fdef)
constraintName
childfields
escapedParentFields
(foreignFieldCascade fdef)
constraintName =
foreignConstraintNameDBName fdef
(childfields, parentfields) =
unzip (map (\((_,b),(_,d)) -> (b,d)) (foreignFields fdef))
escapedParentFields =
map escapeF parentfields
addTable :: [Column] -> EntityDef -> AlterDB
addTable cols entity =
AddTable $ T.concat
-- Lower case e: see Database.Persist.Sql.Migration
[ "CREATe TABLE " -- DO NOT FIX THE CAPITALIZATION!
, escapeE name
, "("
, idtxt
, if null nonIdCols then "" else ","
, T.intercalate "," $ map showColumn nonIdCols
, ")"
]
where
nonIdCols =
case entityPrimary entity of
Just _ ->
cols
_ ->
filter (\c -> Just (cName c) /= fmap fieldDB (getEntityIdField entity) ) cols
name =
getEntityDBName entity
idtxt =
case getEntityId entity of
EntityIdNaturalKey pdef ->
T.concat
[ " PRIMARY KEY ("
, T.intercalate "," $ map (escapeF . fieldDB) $ NEL.toList $ compositeFields pdef
, ")"
]
EntityIdField field ->
let defText = defaultAttribute $ fieldAttrs field
sType = fieldSqlType field
in T.concat
[ escapeF $ fieldDB field
, maySerial sType defText
, " PRIMARY KEY UNIQUE"
, mayDefault defText
]
maySerial :: SqlType -> Maybe Text -> Text
maySerial SqlInt64 Nothing = " SERIAL8 "
maySerial sType _ = " " <> showSqlType sType
mayDefault :: Maybe Text -> Text
mayDefault def = case def of
Nothing -> ""
Just d -> " DEFAULT " <> d
type SafeToRemove = Bool
data AlterColumn
= ChangeType Column SqlType Text
| IsNull Column
| NotNull Column
| Add' Column
| Drop Column SafeToRemove
| Default Column Text
| NoDefault Column
| Update' Column Text
| AddReference EntityNameDB ConstraintNameDB [FieldNameDB] [Text] FieldCascade
| DropReference ConstraintNameDB
deriving Show
data AlterTable
= AddUniqueConstraint ConstraintNameDB [FieldNameDB]
| DropConstraint ConstraintNameDB
deriving Show
data AlterDB = AddTable Text
| AlterColumn EntityNameDB AlterColumn
| AlterTable EntityNameDB AlterTable
deriving Show
-- | Returns all of the columns in the given table currently in the database.
getColumns :: (Text -> IO Statement)
-> EntityDef -> [Column]
-> IO [Either Text (Either Column (ConstraintNameDB, [FieldNameDB]))]
getColumns getter def cols = do
let sqlv = T.concat
[ "SELECT "
, "column_name "
, ",is_nullable "
, ",COALESCE(domain_name, udt_name)" -- See DOMAINS below
, ",column_default "
, ",generation_expression "
, ",numeric_precision "
, ",numeric_scale "
, ",character_maximum_length "
, "FROM information_schema.columns "
, "WHERE table_catalog=current_database() "
, "AND table_schema=current_schema() "
, "AND table_name=? "
]
-- DOMAINS Postgres supports the concept of domains, which are data types
-- with optional constraints. An app might make an "email" domain over the
-- varchar type, with a CHECK that the emails are valid In this case the
-- generated SQL should use the domain name: ALTER TABLE users ALTER COLUMN
-- foo TYPE email This code exists to use the domain name (email), instead
-- of the underlying type (varchar). This is tested in
-- EquivalentTypeTest.hs
stmt <- getter sqlv
let vals =
[ PersistText $ unEntityNameDB $ getEntityDBName def
]
columns <- with (stmtQuery stmt vals) (\src -> runConduit $ src .| processColumns .| CL.consume)
let sqlc = T.concat
[ "SELECT "
, "c.constraint_name, "
, "c.column_name "
, "FROM information_schema.key_column_usage AS c, "
, "information_schema.table_constraints AS k "
, "WHERE c.table_catalog=current_database() "
, "AND c.table_catalog=k.table_catalog "
, "AND c.table_schema=current_schema() "
, "AND c.table_schema=k.table_schema "
, "AND c.table_name=? "
, "AND c.table_name=k.table_name "
, "AND c.constraint_name=k.constraint_name "
, "AND NOT k.constraint_type IN ('PRIMARY KEY', 'FOREIGN KEY') "
, "ORDER BY c.constraint_name, c.column_name"
]
stmt' <- getter sqlc
us <- with (stmtQuery stmt' vals) (\src -> runConduit $ src .| helperU)
return $ columns ++ us
where
refMap =
fmap (\cr -> (crTableName cr, crConstraintName cr))
$ Map.fromList
$ foldl' ref [] cols
where
ref rs c =
maybe rs (\r -> (unFieldNameDB $ cName c, r) : rs) (cReference c)
getAll =
CL.mapM $ \x ->
pure $ case x of
[PersistText con, PersistText col] ->
(con, col)
[PersistByteString con, PersistByteString col] ->
(T.decodeUtf8 con, T.decodeUtf8 col)
o ->
error $ "unexpected datatype returned for postgres o="++show o
helperU = do
rows <- getAll .| CL.consume
return $ map (Right . Right . (ConstraintNameDB . fst . head &&& map (FieldNameDB . snd)))
$ groupBy ((==) `on` fst) rows
processColumns =
CL.mapM $ \x'@((PersistText cname) : _) -> do
col <- liftIO $ getColumn getter (getEntityDBName def) x' (Map.lookup cname refMap)
pure $ case col of
Left e -> Left e
Right c -> Right $ Left c
-- | Check if a column name is listed as the "safe to remove" in the entity
-- list.
safeToRemove :: EntityDef -> FieldNameDB -> Bool
safeToRemove def (FieldNameDB colName)
= any (elem FieldAttrSafeToRemove . fieldAttrs)
$ filter ((== FieldNameDB colName) . fieldDB)
$ NEL.toList $ keyAndEntityFields def
getAlters :: [EntityDef]
-> EntityDef
-> ([Column], [(ConstraintNameDB, [FieldNameDB])])
-> ([Column], [(ConstraintNameDB, [FieldNameDB])])
-> ([AlterColumn], [AlterTable])
getAlters defs def (c1, u1) (c2, u2) =
(getAltersC c1 c2, getAltersU u1 u2)
where
getAltersC [] old =
map (\x -> Drop x $ safeToRemove def $ cName x) old
getAltersC (new:news) old =
let (alters, old') = findAlters defs def new old
in alters ++ getAltersC news old'
getAltersU
:: [(ConstraintNameDB, [FieldNameDB])]
-> [(ConstraintNameDB, [FieldNameDB])]
-> [AlterTable]
getAltersU [] old =
map DropConstraint $ filter (not . isManual) $ map fst old
getAltersU ((name, cols):news) old =
case lookup name old of
Nothing ->
AddUniqueConstraint name cols : getAltersU news old
Just ocols ->
let old' = filter (\(x, _) -> x /= name) old
in if sort cols == sort ocols
then getAltersU news old'
else DropConstraint name
: AddUniqueConstraint name cols
: getAltersU news old'
-- Don't drop constraints which were manually added.
isManual (ConstraintNameDB x) = "__manual_" `T.isPrefixOf` x
getColumn
:: (Text -> IO Statement)
-> EntityNameDB
-> [PersistValue]
-> Maybe (EntityNameDB, ConstraintNameDB)
-> IO (Either Text Column)
getColumn getter tableName' [ PersistText columnName
, PersistText isNullable
, PersistText typeName
, defaultValue
, generationExpression
, numericPrecision
, numericScale
, maxlen
] refName_ = runExceptT $ do
defaultValue' <-
case defaultValue of
PersistNull ->
pure Nothing
PersistText t ->
pure $ Just t
_ ->
throwError $ T.pack $ "Invalid default column: " ++ show defaultValue
generationExpression' <-
case generationExpression of
PersistNull ->
pure Nothing
PersistText t ->
pure $ Just t
_ ->
throwError $ T.pack $ "Invalid generated column: " ++ show generationExpression
let typeStr =
case maxlen of
PersistInt64 n ->
T.concat [typeName, "(", T.pack (show n), ")"]
_ ->
typeName
t <- getType typeStr
let cname = FieldNameDB columnName
ref <- lift $ fmap join $ traverse (getRef cname) refName_
return Column
{ cName = cname
, cNull = isNullable == "YES"
, cSqlType = t
, cDefault = fmap stripSuffixes defaultValue'
, cGenerated = fmap stripSuffixes generationExpression'
, cDefaultConstraintName = Nothing
, cMaxLen = Nothing
, cReference = fmap (\(a,b,c,d) -> ColumnReference a b (mkCascade c d)) ref
}
where
mkCascade updText delText =
FieldCascade
{ fcOnUpdate = parseCascade updText
, fcOnDelete = parseCascade delText
}
parseCascade txt =
case txt of
"NO ACTION" ->
Nothing
"CASCADE" ->
Just Cascade
"SET NULL" ->
Just SetNull
"SET DEFAULT" ->
Just SetDefault
"RESTRICT" ->
Just Restrict
_ ->
error $ "Unexpected value in parseCascade: " <> show txt
stripSuffixes t =
loop'
[ "::character varying"
, "::text"
]
where
loop' [] = t
loop' (p:ps) =
case T.stripSuffix p t of
Nothing -> loop' ps
Just t' -> t'
getRef cname (_, refName') = do
let sql = T.concat
[ "SELECT DISTINCT "
, "ccu.table_name, "
, "tc.constraint_name, "
, "rc.update_rule, "
, "rc.delete_rule "
, "FROM information_schema.constraint_column_usage ccu "
, "INNER JOIN information_schema.key_column_usage kcu "
, " ON ccu.constraint_name = kcu.constraint_name "
, "INNER JOIN information_schema.table_constraints tc "
, " ON tc.constraint_name = kcu.constraint_name "
, "LEFT JOIN information_schema.referential_constraints AS rc"
, " ON rc.constraint_name = ccu.constraint_name "
, "WHERE tc.constraint_type='FOREIGN KEY' "
, "AND kcu.ordinal_position=1 "
, "AND kcu.table_name=? "
, "AND kcu.column_name=? "
, "AND tc.constraint_name=?"
]
stmt <- getter sql
cntrs <-
with
(stmtQuery stmt
[ PersistText $ unEntityNameDB tableName'
, PersistText $ unFieldNameDB cname
, PersistText $ unConstraintNameDB refName'
]
)
(\src -> runConduit $ src .| CL.consume)
case cntrs of
[] ->
return Nothing
[[PersistText table, PersistText constraint, PersistText updRule, PersistText delRule]] ->
return $ Just (EntityNameDB table, ConstraintNameDB constraint, updRule, delRule)
xs ->
error $ mconcat
[ "Postgresql.getColumn: error fetching constraints. Expected a single result for foreign key query for table: "
, T.unpack (unEntityNameDB tableName')
, " and column: "
, T.unpack (unFieldNameDB cname)
, " but got: "
, show xs
]
getType "int4" = pure SqlInt32
getType "int8" = pure SqlInt64
getType "varchar" = pure SqlString
getType "text" = pure SqlString
getType "date" = pure SqlDay
getType "bool" = pure SqlBool
getType "timestamptz" = pure SqlDayTime
getType "float4" = pure SqlReal
getType "float8" = pure SqlReal
getType "bytea" = pure SqlBlob
getType "time" = pure SqlTime
getType "numeric" = getNumeric numericPrecision numericScale
getType a = pure $ SqlOther a
getNumeric (PersistInt64 a) (PersistInt64 b) =
pure $ SqlNumeric (fromIntegral a) (fromIntegral b)
getNumeric PersistNull PersistNull = throwError $ T.concat
[ "No precision and scale were specified for the column: "
, columnName
, " in table: "
, unEntityNameDB tableName'
, ". Postgres defaults to a maximum scale of 147,455 and precision of 16383,"
, " which is probably not what you intended."
, " Specify the values as numeric(total_digits, digits_after_decimal_place)."
]
getNumeric a b = throwError $ T.concat
[ "Can not get numeric field precision for the column: "
, columnName
, " in table: "
, unEntityNameDB tableName'
, ". Expected an integer for both precision and scale, "
, "got: "
, T.pack $ show a
, " and "
, T.pack $ show b
, ", respectively."
, " Specify the values as numeric(total_digits, digits_after_decimal_place)."
]
getColumn _ _ columnName _ =
return $ Left $ T.pack $ "Invalid result from information_schema: " ++ show columnName
-- | Intelligent comparison of SQL types, to account for SqlInt32 vs SqlOther integer
sqlTypeEq :: SqlType -> SqlType -> Bool
sqlTypeEq x y =
T.toCaseFold (showSqlType x) == T.toCaseFold (showSqlType y)
findAlters
:: [EntityDef]
-- ^ The list of all entity definitions that persistent is aware of.
-> EntityDef
-- ^ The entity definition for the entity that we're working on.
-> Column
-- ^ The column that we're searching for potential alterations for.
-> [Column]
-> ([AlterColumn], [Column])
findAlters defs edef col@(Column name isNull sqltype def _gen _defConstraintName _maxLen ref) cols =
case List.find (\c -> cName c == name) cols of
Nothing ->
([Add' col], cols)
Just (Column _oldName isNull' sqltype' def' _gen' _defConstraintName' _maxLen' ref') ->
let refDrop Nothing = []
refDrop (Just ColumnReference {crConstraintName=cname}) =
[DropReference cname]
refAdd Nothing = []
refAdd (Just colRef) =
case find ((== crTableName colRef) . getEntityDBName) defs of
Just refdef
| Just _oldName /= fmap fieldDB (getEntityIdField edef)
->
[AddReference
(getEntityDBName edef)
(crConstraintName colRef)
[name]
(NEL.toList $ Util.dbIdColumnsEsc escapeF refdef)
(crFieldCascade colRef)
]
Just _ -> []
Nothing ->
error $ "could not find the entityDef for reftable["
++ show (crTableName colRef) ++ "]"
modRef =
if equivalentRef ref ref'
then []
else refDrop ref' ++ refAdd ref
modNull = case (isNull, isNull') of
(True, False) -> do
guard $ Just name /= fmap fieldDB (getEntityIdField edef)
pure (IsNull col)
(False, True) ->
let up = case def of
Nothing -> id
Just s -> (:) (Update' col s)
in up [NotNull col]
_ -> []
modType
| sqlTypeEq sqltype sqltype' = []
-- When converting from Persistent pre-2.0 databases, we
-- need to make sure that TIMESTAMP WITHOUT TIME ZONE is
-- treated as UTC.
| sqltype == SqlDayTime && sqltype' == SqlOther "timestamp" =
[ChangeType col sqltype $ T.concat
[ " USING "
, escapeF name
, " AT TIME ZONE 'UTC'"
]]
| otherwise = [ChangeType col sqltype ""]
modDef =
if def == def'
|| isJust (T.stripPrefix "nextval" =<< def')
then []
else
case def of
Nothing -> [NoDefault col]
Just s -> [Default col s]
in
( modRef ++ modDef ++ modNull ++ modType
, filter (\c -> cName c /= name) cols
)
-- We check if we should alter a foreign key. This is almost an equality check,
-- except we consider 'Nothing' and 'Just Restrict' equivalent.
equivalentRef :: Maybe ColumnReference -> Maybe ColumnReference -> Bool
equivalentRef Nothing Nothing = True
equivalentRef (Just cr1) (Just cr2) =
crTableName cr1 == crTableName cr2
&& crConstraintName cr1 == crConstraintName cr2
&& eqCascade (fcOnUpdate $ crFieldCascade cr1) (fcOnUpdate $ crFieldCascade cr2)
&& eqCascade (fcOnDelete $ crFieldCascade cr1) (fcOnDelete $ crFieldCascade cr2)
where
eqCascade :: Maybe CascadeAction -> Maybe CascadeAction -> Bool
eqCascade Nothing Nothing = True
eqCascade Nothing (Just Restrict) = True
eqCascade (Just Restrict) Nothing = True
eqCascade (Just cs1) (Just cs2) = cs1 == cs2
eqCascade _ _ = False
equivalentRef _ _ = False
-- | Get the references to be added to a table for the given column.
getAddReference
:: [EntityDef]
-> EntityDef
-> FieldNameDB
-> ColumnReference
-> Maybe AlterDB
getAddReference allDefs entity cname cr@ColumnReference {crTableName = s, crConstraintName=constraintName} = do
guard $ Just cname /= fmap fieldDB (getEntityIdField entity)
pure $ AlterColumn
table
(AddReference s constraintName [cname] id_ (crFieldCascade cr)
)
where
table = getEntityDBName entity
id_ =
fromMaybe
(error $ "Could not find ID of entity " ++ show s)
$ do
entDef <- find ((== s) . getEntityDBName) allDefs
return $ NEL.toList $ Util.dbIdColumnsEsc escapeF entDef
showColumn :: Column -> Text
showColumn (Column n nu sqlType' def gen _defConstraintName _maxLen _ref) = T.concat
[ escapeF n
, " "
, showSqlType sqlType'
, " "
, if nu then "NULL" else "NOT NULL"
, case def of
Nothing -> ""
Just s -> " DEFAULT " <> s
, case gen of
Nothing -> ""
Just s -> " GENERATED ALWAYS AS (" <> s <> ") STORED"
]
showSqlType :: SqlType -> Text
showSqlType SqlString = "VARCHAR"
showSqlType SqlInt32 = "INT4"
showSqlType SqlInt64 = "INT8"
showSqlType SqlReal = "DOUBLE PRECISION"
showSqlType (SqlNumeric s prec) = T.concat [ "NUMERIC(", T.pack (show s), ",", T.pack (show prec), ")" ]
showSqlType SqlDay = "DATE"
showSqlType SqlTime = "TIME"
showSqlType SqlDayTime = "TIMESTAMP WITH TIME ZONE"
showSqlType SqlBlob = "BYTEA"
showSqlType SqlBool = "BOOLEAN"
-- Added for aliasing issues re: https://github.com/yesodweb/yesod/issues/682
showSqlType (SqlOther (T.toLower -> "integer")) = "INT4"
showSqlType (SqlOther t) = t
showAlterDb :: AlterDB -> (Bool, Text)
showAlterDb (AddTable s) = (False, s)
showAlterDb (AlterColumn t ac) =
(isUnsafe ac, showAlter t ac)
where
isUnsafe (Drop _ safeRemove) = not safeRemove
isUnsafe _ = False
showAlterDb (AlterTable t at) = (False, showAlterTable t at)
showAlterTable :: EntityNameDB -> AlterTable -> Text
showAlterTable table (AddUniqueConstraint cname cols) = T.concat
[ "ALTER TABLE "
, escapeE table
, " ADD CONSTRAINT "
, escapeC cname
, " UNIQUE("
, T.intercalate "," $ map escapeF cols
, ")"
]
showAlterTable table (DropConstraint cname) = T.concat
[ "ALTER TABLE "
, escapeE table
, " DROP CONSTRAINT "
, escapeC cname
]
showAlter :: EntityNameDB -> AlterColumn -> Text
showAlter table (ChangeType c t extra) =
T.concat
[ "ALTER TABLE "
, escapeE table
, " ALTER COLUMN "
, escapeF (cName c)
, " TYPE "
, showSqlType t
, extra
]
showAlter table (IsNull c) =
T.concat
[ "ALTER TABLE "
, escapeE table
, " ALTER COLUMN "
, escapeF (cName c)
, " DROP NOT NULL"
]
showAlter table (NotNull c) =
T.concat
[ "ALTER TABLE "
, escapeE table
, " ALTER COLUMN "
, escapeF (cName c)
, " SET NOT NULL"
]
showAlter table (Add' col) =
T.concat
[ "ALTER TABLE "
, escapeE table
, " ADD COLUMN "
, showColumn col
]
showAlter table (Drop c _) =
T.concat
[ "ALTER TABLE "
, escapeE table
, " DROP COLUMN "
, escapeF (cName c)
]
showAlter table (Default c s) =
T.concat
[ "ALTER TABLE "
, escapeE table
, " ALTER COLUMN "
, escapeF (cName c)
, " SET DEFAULT "
, s
]
showAlter table (NoDefault c) = T.concat
[ "ALTER TABLE "
, escapeE table
, " ALTER COLUMN "
, escapeF (cName c)
, " DROP DEFAULT"
]
showAlter table (Update' c s) = T.concat
[ "UPDATE "
, escapeE table
, " SET "
, escapeF (cName c)
, "="
, s
, " WHERE "
, escapeF (cName c)
, " IS NULL"
]
showAlter table (AddReference reftable fkeyname t2 id2 cascade) = T.concat
[ "ALTER TABLE "
, escapeE table
, " ADD CONSTRAINT "
, escapeC fkeyname
, " FOREIGN KEY("
, T.intercalate "," $ map escapeF t2
, ") REFERENCES "
, escapeE reftable
, "("
, T.intercalate "," id2
, ")"
] <> renderFieldCascade cascade
showAlter table (DropReference cname) = T.concat
[ "ALTER TABLE "
, escapeE table
, " DROP CONSTRAINT "
, escapeC cname
]
-- | Get the SQL string for the table that a PeristEntity represents.
-- Useful for raw SQL queries.
tableName :: (PersistEntity record) => record -> Text
tableName = escapeE . tableDBName
-- | Get the SQL string for the field that an EntityField represents.
-- Useful for raw SQL queries.
fieldName :: (PersistEntity record) => EntityField record typ -> Text
fieldName = escapeF . fieldDBName
escapeC :: ConstraintNameDB -> Text
escapeC = escapeWith escape
escapeE :: EntityNameDB -> Text
escapeE = escapeWith escape
escapeF :: FieldNameDB -> Text
escapeF = escapeWith escape
escape :: Text -> Text
escape s =
T.pack $ '"' : go (T.unpack s) ++ "\""
where
go "" = ""
go ('"':xs) = "\"\"" ++ go xs
go (x:xs) = x : go xs
-- | Information required to connect to a PostgreSQL database
-- using @persistent@'s generic facilities. These values are the
-- same that are given to 'withPostgresqlPool'.
data PostgresConf = PostgresConf
{ pgConnStr :: ConnectionString
-- ^ The connection string.
-- TODO: Currently stripes, idle timeout, and pool size are all separate fields
-- When Persistent next does a large breaking release (3.0?), we should consider making these just a single ConnectionPoolConfig value
--
-- Currently there the idle timeout is an Integer, rather than resource-pool's NominalDiffTime type.
-- This is because the time package only recently added the Read instance for NominalDiffTime.
-- Future TODO: Consider removing the Read instance, and/or making the idle timeout a NominalDiffTime.
, pgPoolStripes :: Int
-- ^ How many stripes to divide the pool into. See "Data.Pool" for details.
-- @since 2.11.0.0
, pgPoolIdleTimeout :: Integer -- Ideally this would be a NominalDiffTime, but that type lacks a Read instance https://github.com/haskell/time/issues/130
-- ^ How long connections can remain idle before being disposed of, in seconds.
-- @since 2.11.0.0
, pgPoolSize :: Int
-- ^ How many connections should be held in the connection pool.
} deriving (Show, Read, Data)
instance FromJSON PostgresConf where
parseJSON v = modifyFailure ("Persistent: error loading PostgreSQL conf: " ++) $
flip (withObject "PostgresConf") v $ \o -> do
let defaultPoolConfig = defaultConnectionPoolConfig
database <- o .: "database"
host <- o .: "host"
port <- o .:? "port" .!= 5432
user <- o .: "user"
password <- o .: "password"
poolSize <- o .:? "poolsize" .!= (connectionPoolConfigSize defaultPoolConfig)
poolStripes <- o .:? "stripes" .!= (connectionPoolConfigStripes defaultPoolConfig)
poolIdleTimeout <- o .:? "idleTimeout" .!= (floor $ connectionPoolConfigIdleTimeout defaultPoolConfig)
let ci = PG.ConnectInfo
{ PG.connectHost = host
, PG.connectPort = port
, PG.connectUser = user
, PG.connectPassword = password
, PG.connectDatabase = database
}
cstr = PG.postgreSQLConnectionString ci
return $ PostgresConf cstr poolStripes poolIdleTimeout poolSize
instance PersistConfig PostgresConf where
type PersistConfigBackend PostgresConf = SqlPersistT
type PersistConfigPool PostgresConf = ConnectionPool
createPoolConfig conf = runNoLoggingT $ createPostgresqlPoolWithConf conf defaultPostgresConfHooks
runPool _ = runSqlPool
loadConfig = parseJSON
applyEnv c0 = do
env <- getEnvironment
return $ addUser env
$ addPass env
$ addDatabase env
$ addPort env
$ addHost env c0
where
addParam param val c =
c { pgConnStr = B8.concat [pgConnStr c, " ", param, "='", pgescape val, "'"] }
pgescape = B8.pack . go
where
go ('\'':rest) = '\\' : '\'' : go rest
go ('\\':rest) = '\\' : '\\' : go rest
go ( x :rest) = x : go rest
go [] = []
maybeAddParam param envvar env =
maybe id (addParam param) $
lookup envvar env
addHost = maybeAddParam "host" "PGHOST"
addPort = maybeAddParam "port" "PGPORT"
addUser = maybeAddParam "user" "PGUSER"
addPass = maybeAddParam "password" "PGPASS"
addDatabase = maybeAddParam "dbname" "PGDATABASE"
-- | Hooks for configuring the Persistent/its connection to Postgres
--
-- @since 2.11.0
data PostgresConfHooks = PostgresConfHooks
{ pgConfHooksGetServerVersion :: PG.Connection -> IO (NonEmpty Word)
-- ^ Function to get the version of Postgres
--
-- The default implementation queries the server with "show server_version".
-- Some variants of Postgres, such as Redshift, don't support showing the version.
-- It's recommended you return a hardcoded version in those cases.
--
-- @since 2.11.0
, pgConfHooksAfterCreate :: PG.Connection -> IO ()
-- ^ Action to perform after a connection is created.
--
-- Typical uses of this are modifying the connection (e.g. to set the schema) or logging a connection being created.
--
-- The default implementation does nothing.
--
-- @since 2.11.0
}
-- | Default settings for 'PostgresConfHooks'. See the individual fields of 'PostgresConfHooks' for the default values.
--
-- @since 2.11.0
defaultPostgresConfHooks :: PostgresConfHooks
defaultPostgresConfHooks = PostgresConfHooks
{ pgConfHooksGetServerVersion = getServerVersionNonEmpty
, pgConfHooksAfterCreate = const $ pure ()
}
refName :: EntityNameDB -> FieldNameDB -> ConstraintNameDB
refName (EntityNameDB table) (FieldNameDB column) =
let overhead = T.length $ T.concat ["_", "_fkey"]
(fromTable, fromColumn) = shortenNames overhead (T.length table, T.length column)
in ConstraintNameDB $ T.concat [T.take fromTable table, "_", T.take fromColumn column, "_fkey"]
where
-- Postgres automatically truncates too long foreign keys to a combination of
-- truncatedTableName + "_" + truncatedColumnName + "_fkey"
-- This works fine for normal use cases, but it creates an issue for Persistent
-- Because after running the migrations, Persistent sees the truncated foreign key constraint
-- doesn't have the expected name, and suggests that you migrate again
-- To workaround this, we copy the Postgres truncation approach before sending foreign key constraints to it.
--
-- I believe this will also be an issue for extremely long table names,
-- but it's just much more likely to exist with foreign key constraints because they're usually tablename * 2 in length
-- Approximation of the algorithm Postgres uses to truncate identifiers
-- See makeObjectName https://github.com/postgres/postgres/blob/5406513e997f5ee9de79d4076ae91c04af0c52f6/src/backend/commands/indexcmds.c#L2074-L2080
shortenNames :: Int -> (Int, Int) -> (Int, Int)
shortenNames overhead (x, y)
| x + y + overhead <= maximumIdentifierLength = (x, y)
| x > y = shortenNames overhead (x - 1, y)
| otherwise = shortenNames overhead (x, y - 1)
-- | Postgres' default maximum identifier length in bytes
-- (You can re-compile Postgres with a new limit, but I'm assuming that virtually noone does this).
-- See https://www.postgresql.org/docs/11/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS
maximumIdentifierLength :: Int
maximumIdentifierLength = 63
udToPair :: UniqueDef -> (ConstraintNameDB, [FieldNameDB])
udToPair ud = (uniqueDBName ud, map snd $ NEL.toList $ uniqueFields ud)
mockMigrate :: [EntityDef]
-> (Text -> IO Statement)
-> EntityDef
-> IO (Either [Text] [(Bool, Text)])
mockMigrate allDefs _ entity = fmap (fmap $ map showAlterDb) $ do
case partitionEithers [] of
([], old'') -> return $ Right $ migrationText False old''
(errs, _) -> return $ Left errs
where
name = getEntityDBName entity
migrationText exists' old'' =
if not exists'
then createText newcols fdefs udspair
else let (acs, ats) = getAlters allDefs entity (newcols, udspair) old'
acs' = map (AlterColumn name) acs
ats' = map (AlterTable name) ats
in acs' ++ ats'
where
old' = partitionEithers old''
(newcols', udefs, fdefs) = postgresMkColumns allDefs entity
newcols = filter (not . safeToRemove entity . cName) newcols'
udspair = map udToPair udefs
-- Check for table existence if there are no columns, workaround
-- for https://github.com/yesodweb/persistent/issues/152
createText newcols fdefs udspair =
(addTable newcols entity) : uniques ++ references ++ foreignsAlt
where
uniques = flip concatMap udspair $ \(uname, ucols) ->
[AlterTable name $ AddUniqueConstraint uname ucols]
references =
mapMaybe
(\Column { cName, cReference } ->
getAddReference allDefs entity cName =<< cReference
)
newcols
foreignsAlt = mapMaybe (mkForeignAlt entity) fdefs
-- | Mock a migration even when the database is not present.
-- This function performs the same functionality of 'printMigration'
-- with the difference that an actual database is not needed.
mockMigration :: Migration -> IO ()
mockMigration mig = do
smap <- newIORef $ Map.empty
let sqlbackend =
mkSqlBackend MkSqlBackendArgs
{ connPrepare = \_ -> do
return Statement
{ stmtFinalize = return ()
, stmtReset = return ()
, stmtExecute = undefined
, stmtQuery = \_ -> return $ return ()
}
, connInsertSql = undefined
, connStmtMap = smap
, connClose = undefined
, connMigrateSql = mockMigrate
, connBegin = undefined
, connCommit = undefined
, connRollback = undefined
, connEscapeFieldName = escapeF
, connEscapeTableName = escapeE . getEntityDBName
, connEscapeRawName = escape
, connNoLimit = undefined
, connRDBMS = undefined
, connLimitOffset = undefined
, connLogFunc = undefined
}
result = runReaderT $ runWriterT $ runWriterT mig
resp <- result sqlbackend
mapM_ T.putStrLn $ map snd $ snd resp
putManySql :: EntityDef -> Int -> Text
putManySql ent n = putManySql' conflictColumns fields ent n
where
fields = getEntityFieldsDatabase ent
conflictColumns = concatMap (map (escapeF . snd) . NEL.toList . uniqueFields) (getEntityUniques ent)
repsertManySql :: EntityDef -> Int -> Text
repsertManySql ent n = putManySql' conflictColumns fields ent n
where
fields = NEL.toList $ keyAndEntityFields ent
conflictColumns = NEL.toList $ escapeF . fieldDB <$> getEntityKeyFields ent
-- | This type is used to determine how to update rows using Postgres'
-- @INSERT ... ON CONFLICT KEY UPDATE@ functionality, exposed via
-- 'upsertWhere' and 'upsertManyWhere' in this library.
--
-- @since 2.12.1.0
data HandleUpdateCollision record where
-- | Copy the field directly from the record.
CopyField :: EntityField record typ -> HandleUpdateCollision record
-- | Only copy the field if it is not equal to the provided value.
CopyUnlessEq :: PersistField typ => EntityField record typ -> typ -> HandleUpdateCollision record
-- | Copy the field into the database only if the value in the
-- corresponding record is non-@NULL@.
--
-- @since 2.12.1.0
copyUnlessNull :: PersistField typ => EntityField record (Maybe typ) -> HandleUpdateCollision record
copyUnlessNull field = CopyUnlessEq field Nothing
-- | Copy the field into the database only if the value in the
-- corresponding record is non-empty, where "empty" means the Monoid
-- definition for 'mempty'. Useful for 'Text', 'String', 'ByteString', etc.
--
-- The resulting 'HandleUpdateCollision' type is useful for the
-- 'upsertManyWhere' function.
--
-- @since 2.12.1.0
copyUnlessEmpty :: (Monoid.Monoid typ, PersistField typ) => EntityField record typ -> HandleUpdateCollision record
copyUnlessEmpty field = CopyUnlessEq field Monoid.mempty
-- | Copy the field into the database only if the field is not equal to the
-- provided value. This is useful to avoid copying weird nullary data into
-- the database.
--
-- The resulting 'HandleUpdateCollision' type is useful for the
-- 'upsertMany' function.
--
-- @since 2.12.1.0
copyUnlessEq :: PersistField typ => EntityField record typ -> typ -> HandleUpdateCollision record
copyUnlessEq = CopyUnlessEq
-- | Copy the field directly from the record.
--
-- @since 2.12.1.0
copyField :: PersistField typ => EntityField record typ -> HandleUpdateCollision record
copyField = CopyField
-- | Postgres specific 'upsertWhere'. This method does the following:
-- It will insert a record if no matching unique key exists.
-- If a unique key exists, it will update the relevant field with a user-supplied value, however,
-- it will only do this update on a user-supplied condition.
-- For example, here's how this method could be called like such:
--
-- @
-- upsertWhere record [recordField =. newValue] [recordField /= newValue]
-- @
--
-- Called thusly, this method will insert a new record (if none exists) OR update a recordField with a new value
-- assuming the condition in the last block is met.
--
-- @since 2.12.1.0
upsertWhere
:: ( backend ~ PersistEntityBackend record
, PersistEntity record
, PersistEntityBackend record ~ SqlBackend
, MonadIO m
, PersistStore backend
, BackendCompatible SqlBackend backend
, OnlyOneUniqueKey record
)
=> record
-> [Update record]
-> [Filter record]
-> ReaderT backend m ()
upsertWhere record updates filts =
upsertManyWhere [record] [] updates filts
-- | Postgres specific 'upsertManyWhere'. This method does the following:
-- It will insert a record if no matching unique key exists.
-- If a unique key exists, it will update the relevant field with a user-supplied value, however,
-- it will only do this update on a user-supplied condition.
-- For example, here's how this method could be called like such:
--
-- upsertManyWhere [record] [recordField =. newValue] [recordField !=. newValue]
--
-- Called thusly, this method will insert a new record (if none exists) OR update a recordField with a new value
-- assuming the condition in the last block is met.
--
-- @since 2.12.1.0
upsertManyWhere
:: forall record backend m.
( backend ~ PersistEntityBackend record
, BackendCompatible SqlBackend backend
, PersistEntityBackend record ~ SqlBackend
, PersistEntity record
, OnlyOneUniqueKey record
, MonadIO m
)
=> [record]
-- ^ A list of the records you want to insert, or update
-> [HandleUpdateCollision record]
-- ^ A list of the fields you want to copy over.
-> [Update record]
-- ^ A list of the updates to apply that aren't dependent on the record
-- being inserted.
-> [Filter record]
-- ^ A filter condition that dictates the scope of the updates
-> ReaderT backend m ()
upsertManyWhere [] _ _ _ = return ()
upsertManyWhere records fieldValues updates filters = do
conn <- asks projectBackend
let uniqDef = onlyOneUniqueDef (Proxy :: Proxy record)
uncurry rawExecute $
mkBulkUpsertQuery records conn fieldValues updates filters uniqDef
-- | Exclude any record field if it doesn't match the filter record. Used only in `upsertWhere` and
-- `upsertManyWhere`
--
-- TODO: we could probably make a sum type for the `Filter` record that's passed into the `upsertWhere` and
-- `upsertManyWhere` methods that has similar behavior to the HandleCollisionUpdate type.
--
-- @since 2.12.1.0
excludeNotEqualToOriginal
:: (PersistField typ, PersistEntity rec)
=> EntityField rec typ
-> Filter rec
excludeNotEqualToOriginal field =
Filter
{ filterField =
field
, filterFilter =
Ne
, filterValue =
UnsafeValue $
PersistLiteral_
Unescaped
bsForExcludedField
}
where
bsForExcludedField =
T.encodeUtf8
$ "EXCLUDED."
<> fieldName field
-- | This creates the query for 'upsertManyWhere'. If you
-- provide an empty list of updates to perform, then it will generate
-- a dummy/no-op update using the first field of the record. This avoids
-- duplicate key exceptions.
mkBulkUpsertQuery
:: (PersistEntity record, PersistEntityBackend record ~ SqlBackend, OnlyOneUniqueKey record)
=> [record]
-- ^ A list of the records you want to insert, or update
-> SqlBackend
-> [HandleUpdateCollision record]
-- ^ A list of the fields you want to copy over.
-> [Update record]
-- ^ A list of the updates to apply that aren't dependent on the record being inserted.
-> [Filter record]
-- ^ A filter condition that dictates the scope of the updates
-> UniqueDef
-- ^ The specific uniqueness constraint to use on the record. Postgres
-- rquires that we use exactly one relevant constraint, and it can't do
-- a catch-all. How frustrating!
-> (Text, [PersistValue])
mkBulkUpsertQuery records conn fieldValues updates filters uniqDef =
(q, recordValues <> updsValues <> copyUnlessValues <> whereVals)
where
mfieldDef x = case x of
CopyField rec -> Right (fieldDbToText (persistFieldDef rec))
CopyUnlessEq rec val -> Left (fieldDbToText (persistFieldDef rec), toPersistValue val)
(fieldsToMaybeCopy, updateFieldNames) = partitionEithers $ map mfieldDef fieldValues
fieldDbToText = escapeF . fieldDB
entityDef' = entityDef records
conflictColumns =
map (escapeF . snd) $ NEL.toList $ uniqueFields uniqDef
firstField = case entityFieldNames of
[] -> error "The entity you're trying to insert does not have any fields."
(field:_) -> field
entityFieldNames = map fieldDbToText (getEntityFieldsDatabase entityDef')
nameOfTable = escapeE . getEntityDBName $ entityDef'
copyUnlessValues = map snd fieldsToMaybeCopy
recordValues = concatMap (map toPersistValue . toPersistFields) records
recordPlaceholders =
Util.commaSeparated
$ map (Util.parenWrapped . Util.commaSeparated . map (const "?") . toPersistFields)
$ records
mkCondFieldSet n _ =
T.concat
[ n
, "=COALESCE("
, "NULLIF("
, "EXCLUDED."
, n
, ","
, "?"
, ")"
, ","
, nameOfTable
, "."
, n
,")"
]
condFieldSets = map (uncurry mkCondFieldSet) fieldsToMaybeCopy
fieldSets = map (\n -> T.concat [n, "=EXCLUDED.", n, ""]) updateFieldNames
upds = map (Util.mkUpdateText' (escapeF) (\n -> T.concat [nameOfTable, ".", n])) updates
updsValues = map (\(Update _ val _) -> toPersistValue val) updates
(wher, whereVals) =
if null filters
then ("", [])
else (filterClauseWithVals (Just PrefixTableName) conn filters)
updateText =
case fieldSets <> upds <> condFieldSets of
[] ->
-- This case is really annoying, and probably unlikely to be
-- actually hit - someone would have had to call something like
-- `upsertManyWhere [] [] []`, but that would have been caught
-- by the prior case.
-- Would be nice to have something like a `NonEmpty (These ...)`
-- instead of multiple lists...
T.concat [firstField, "=", nameOfTable, ".", firstField]
xs ->
Util.commaSeparated xs
q = T.concat
[ "INSERT INTO "
, nameOfTable
, Util.parenWrapped . Util.commaSeparated $ entityFieldNames
, " VALUES "
, recordPlaceholders
, " ON CONFLICT "
, Util.parenWrapped $ Util.commaSeparated $ conflictColumns
, " DO UPDATE SET "
, updateText
, wher
]
putManySql' :: [Text] -> [FieldDef] -> EntityDef -> Int -> Text
putManySql' conflictColumns (filter isFieldNotGenerated -> fields) ent n = q
where
fieldDbToText = escapeF . fieldDB
mkAssignment f = T.concat [f, "=EXCLUDED.", f]
table = escapeE . getEntityDBName $ ent
columns = Util.commaSeparated $ map fieldDbToText fields
placeholders = map (const "?") fields
updates = map (mkAssignment . fieldDbToText) fields
q = T.concat
[ "INSERT INTO "
, table
, Util.parenWrapped columns
, " VALUES "
, Util.commaSeparated . replicate n
. Util.parenWrapped . Util.commaSeparated $ placeholders
, " ON CONFLICT "
, Util.parenWrapped . Util.commaSeparated $ conflictColumns
, " DO UPDATE SET "
, Util.commaSeparated updates
]
-- | Enable a Postgres extension. See https://www.postgresql.org/docs/current/static/contrib.html
-- for a list.
migrateEnableExtension :: Text -> Migration
migrateEnableExtension extName = WriterT $ WriterT $ do
res :: [Single Int] <-
rawSql "SELECT COUNT(*) FROM pg_catalog.pg_extension WHERE extname = ?" [PersistText extName]
if res == [Single 0]
then return (((), []) , [(False, "CREATe EXTENSION \"" <> extName <> "\"")])
else return (((), []), [])
postgresMkColumns :: [EntityDef] -> EntityDef -> ([Column], [UniqueDef], [ForeignDef])
postgresMkColumns allDefs t =
mkColumns allDefs t
$ setBackendSpecificForeignKeyName refName emptyBackendSpecificOverrides