persistent-mysql-2.10.3: Database/Persist/MySQL.hs
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE ExistentialQuantification #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE PatternSynonyms #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE ViewPatterns #-}
{-# OPTIONS_GHC -fno-warn-deprecations #-} -- Pattern match 'PersistDbSpecific'
-- | A MySQL backend for @persistent@.
module Database.Persist.MySQL
( withMySQLPool
, withMySQLConn
, createMySQLPool
, module Database.Persist.Sql
, MySQL.ConnectInfo(..)
, MySQLBase.SSLInfo(..)
, MySQL.defaultConnectInfo
, MySQLBase.defaultSSLInfo
, MySQLConf(..)
, mockMigration
-- * @ON DUPLICATE KEY UPDATE@ Functionality
, insertOnDuplicateKeyUpdate
, insertManyOnDuplicateKeyUpdate
, HandleUpdateCollision
, pattern SomeField
, SomeField
, copyField
, copyUnlessNull
, copyUnlessEmpty
, copyUnlessEq
) where
import qualified Blaze.ByteString.Builder.Char8 as BBB
import qualified Blaze.ByteString.Builder.ByteString as BBS
import Control.Arrow
import Control.Monad
import Control.Monad.IO.Class (MonadIO (..))
import Control.Monad.IO.Unlift (MonadUnliftIO)
import Control.Monad.Logger (MonadLogger, runNoLoggingT)
import Control.Monad.Trans.Class (lift)
import Control.Monad.Trans.Except (ExceptT, runExceptT)
import Control.Monad.Trans.Reader (runReaderT, ReaderT)
import Control.Monad.Trans.Writer (runWriterT)
import GHC.Stack
import Data.Conduit
import qualified Data.Conduit.List as CL
import Data.Acquire (Acquire, mkAcquire, with)
import Data.Aeson
import Data.Aeson.Types (modifyFailure)
import Data.ByteString (ByteString)
import Data.Either (partitionEithers)
import Data.Fixed (Pico)
import Data.Function (on)
import Data.Int (Int64)
import Data.IORef
import Data.List (find, intercalate, sort, groupBy)
import qualified Data.Map as Map
import Data.Maybe (listToMaybe, mapMaybe, fromMaybe)
import Data.Monoid ((<>))
import qualified Data.Monoid as Monoid
import Data.Pool (Pool)
import Data.Text (Text, pack)
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import qualified Data.Text.IO as T
import System.Environment (getEnvironment)
import Database.Persist.Sql
import Database.Persist.Sql.Types.Internal (makeIsolationLevelStatement)
import qualified Database.Persist.Sql.Util as Util
import qualified Database.MySQL.Base as MySQLBase
import qualified Database.MySQL.Base.Types as MySQLBase
import qualified Database.MySQL.Simple as MySQL
import qualified Database.MySQL.Simple.Param as MySQL
import qualified Database.MySQL.Simple.Result as MySQL
import qualified Database.MySQL.Simple.Types as MySQL
-- | Create a MySQL 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 be already been released.
withMySQLPool :: (MonadLogger m, MonadUnliftIO m)
=> MySQL.ConnectInfo
-- ^ Connection information.
-> 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
withMySQLPool ci = withSqlPool $ open' ci
-- | Create a MySQL connection pool. Note that it's your
-- responsibility to properly close the connection pool when
-- unneeded. Use 'withMySQLPool' for automatic resource control.
createMySQLPool :: (MonadUnliftIO m, MonadLogger m)
=> MySQL.ConnectInfo
-- ^ Connection information.
-> Int
-- ^ Number of connections to be kept open in the pool.
-> m (Pool SqlBackend)
createMySQLPool ci = createSqlPool $ open' ci
-- | Same as 'withMySQLPool', but instead of opening a pool
-- of connections, only one connection is opened.
withMySQLConn :: (MonadUnliftIO m, MonadLogger m)
=> MySQL.ConnectInfo
-- ^ Connection information.
-> (SqlBackend -> m a)
-- ^ Action to be executed that uses the connection.
-> m a
withMySQLConn = withSqlConn . open'
-- | Internal function that opens a connection to the MySQL
-- server.
open' :: MySQL.ConnectInfo -> LogFunc -> IO SqlBackend
open' ci logFunc = do
conn <- MySQL.connect ci
MySQLBase.autocommit conn False -- disable autocommit!
smap <- newIORef $ Map.empty
return $ SqlBackend
{ connPrepare = prepare' conn
, connStmtMap = smap
, connInsertSql = insertSql'
, connInsertManySql = Nothing
, connUpsertSql = Nothing
, connPutManySql = Just putManySql
, connClose = MySQL.close conn
, connMigrateSql = migrate' ci
, connBegin = \_ mIsolation -> do
forM_ mIsolation $ \iso -> MySQL.execute_ conn (makeIsolationLevelStatement iso)
MySQL.execute_ conn "start transaction" >> return ()
, connCommit = const $ MySQL.commit conn
, connRollback = const $ MySQL.rollback conn
, connEscapeName = pack . escapeDBName
, connNoLimit = "LIMIT 18446744073709551615"
-- This noLimit is suggested by MySQL's own docs, see
-- <http://dev.mysql.com/doc/refman/5.5/en/select.html>
, connRDBMS = "mysql"
, connLimitOffset = decorateSQLWithLimitOffset "LIMIT 18446744073709551615"
, connLogFunc = logFunc
, connMaxParams = Nothing
, connRepsertManySql = Just repsertManySql
}
-- | Prepare a query. We don't support prepared statements, but
-- we'll do some client-side preprocessing here.
prepare' :: MySQL.Connection -> Text -> IO Statement
prepare' conn sql = do
let query = MySQL.Query (T.encodeUtf8 sql)
return Statement
{ stmtFinalize = return ()
, stmtReset = return ()
, stmtExecute = execute' conn query
, stmtQuery = withStmt' conn query
}
-- | SQL code to be executed when inserting an entity.
insertSql' :: EntityDef -> [PersistValue] -> InsertSqlResult
insertSql' ent vals =
case entityPrimary ent of
Just _ -> ISRManyKeys sql vals
Nothing -> ISRInsertGet sql "SELECT LAST_INSERT_ID()"
where
(fieldNames, placeholders) = unzip (Util.mkInsertPlaceholders ent escape)
sql = T.concat
[ "INSERT INTO "
, escape $ entityDB ent
, "("
, T.intercalate "," fieldNames
, ") VALUES("
, T.intercalate "," placeholders
, ")"
]
-- | Execute an statement that doesn't return any results.
execute' :: MySQL.Connection -> MySQL.Query -> [PersistValue] -> IO Int64
execute' conn query vals = MySQL.execute conn query (map P vals)
-- | Execute an statement that does return results. The results
-- are fetched all at once and stored into memory.
withStmt' :: MonadIO m
=> MySQL.Connection
-> MySQL.Query
-> [PersistValue]
-> Acquire (ConduitM () [PersistValue] m ())
withStmt' conn query vals = do
result <- mkAcquire createResult MySQLBase.freeResult
return $ fetchRows result >>= CL.sourceList
where
createResult = do
-- Execute the query
formatted <- MySQL.formatQuery conn query (map P vals)
MySQLBase.query conn formatted
MySQLBase.storeResult conn
fetchRows result = liftIO $ do
-- Find out the type of the columns
fields <- MySQLBase.fetchFields result
let getters = [ maybe PersistNull (getGetter f f . Just) | f <- fields]
convert = use getters
where use (g:gs) (col:cols) =
let !v = g col
!vs = use gs cols
in (v:vs)
use _ _ = []
-- Ready to go!
let go acc = do
row <- MySQLBase.fetchRow result
case row of
[] -> return (acc [])
_ -> let !converted = convert row
in go (acc . (converted:))
go id
-- | @newtype@ around 'PersistValue' that supports the
-- 'MySQL.Param' type class.
newtype P = P PersistValue
instance MySQL.Param P where
render (P (PersistText t)) = MySQL.render t
render (P (PersistByteString bs)) = MySQL.render bs
render (P (PersistInt64 i)) = MySQL.render i
render (P (PersistDouble d)) = MySQL.render d
render (P (PersistBool b)) = MySQL.render b
render (P (PersistDay d)) = MySQL.render d
render (P (PersistTimeOfDay t)) = MySQL.render t
render (P (PersistUTCTime t)) = MySQL.render t
render (P PersistNull) = MySQL.render MySQL.Null
render (P (PersistList l)) = MySQL.render $ listToJSON l
render (P (PersistMap m)) = MySQL.render $ mapToJSON m
render (P (PersistRational r)) =
MySQL.Plain $ BBB.fromString $ show (fromRational r :: Pico)
-- FIXME: Too Ambiguous, can not select precision without information about field
render (P (PersistDbSpecific s)) = MySQL.Plain $ BBS.fromByteString s
render (P (PersistLiteral l)) = MySQL.Plain $ BBS.fromByteString l
render (P (PersistLiteralEscaped e)) = MySQL.Escape e
render (P (PersistArray a)) = MySQL.render (P (PersistList a))
render (P (PersistObjectId _)) =
error "Refusing to serialize a PersistObjectId to a MySQL value"
-- | @Getter a@ is a function that converts an incoming value
-- into a data type @a@.
type Getter a = MySQLBase.Field -> Maybe ByteString -> a
-- | Helper to construct 'Getter'@s@ using 'MySQL.Result'.
convertPV :: MySQL.Result a => (a -> b) -> Getter b
convertPV f = (f .) . MySQL.convert
-- | Get the corresponding @'Getter' 'PersistValue'@ depending on
-- the type of the column.
getGetter :: MySQLBase.Field -> Getter PersistValue
getGetter field = go (MySQLBase.fieldType field)
(MySQLBase.fieldLength field)
(MySQLBase.fieldCharSet field)
where
-- Bool
go MySQLBase.Tiny 1 _ = convertPV PersistBool
go MySQLBase.Tiny _ _ = convertPV PersistInt64
-- Int64
go MySQLBase.Int24 _ _ = convertPV PersistInt64
go MySQLBase.Short _ _ = convertPV PersistInt64
go MySQLBase.Long _ _ = convertPV PersistInt64
go MySQLBase.LongLong _ _ = convertPV PersistInt64
-- Double
go MySQLBase.Float _ _ = convertPV PersistDouble
go MySQLBase.Double _ _ = convertPV PersistDouble
go MySQLBase.Decimal _ _ = convertPV PersistDouble
go MySQLBase.NewDecimal _ _ = convertPV PersistDouble
-- ByteString and Text
-- The MySQL C client (and by extension the Haskell mysql package) doesn't distinguish between binary and non-binary string data at the type level.
-- (e.g. both BLOB and TEXT have the MySQLBase.Blob type).
-- Instead, the character set distinguishes them. Binary data uses character set number 63.
-- See https://dev.mysql.com/doc/refman/5.6/en/c-api-data-structures.html (Search for "63")
go MySQLBase.VarChar _ 63 = convertPV PersistByteString
go MySQLBase.VarString _ 63 = convertPV PersistByteString
go MySQLBase.String _ 63 = convertPV PersistByteString
go MySQLBase.VarChar _ _ = convertPV PersistText
go MySQLBase.VarString _ _ = convertPV PersistText
go MySQLBase.String _ _ = convertPV PersistText
go MySQLBase.Blob _ 63 = convertPV PersistByteString
go MySQLBase.TinyBlob _ 63 = convertPV PersistByteString
go MySQLBase.MediumBlob _ 63 = convertPV PersistByteString
go MySQLBase.LongBlob _ 63 = convertPV PersistByteString
go MySQLBase.Blob _ _ = convertPV PersistText
go MySQLBase.TinyBlob _ _ = convertPV PersistText
go MySQLBase.MediumBlob _ _ = convertPV PersistText
go MySQLBase.LongBlob _ _ = convertPV PersistText
-- Time-related
go MySQLBase.Time _ _ = convertPV PersistTimeOfDay
go MySQLBase.DateTime _ _ = convertPV PersistUTCTime
go MySQLBase.Timestamp _ _ = convertPV PersistUTCTime
go MySQLBase.Date _ _ = convertPV PersistDay
go MySQLBase.NewDate _ _ = convertPV PersistDay
go MySQLBase.Year _ _ = convertPV PersistDay
-- Null
go MySQLBase.Null _ _ = \_ _ -> PersistNull
-- Controversial conversions
go MySQLBase.Set _ _ = convertPV PersistText
go MySQLBase.Enum _ _ = convertPV PersistText
-- Conversion using PersistDbSpecific
go MySQLBase.Geometry _ _ = \_ m ->
case m of
Just g -> PersistLiteral g
Nothing -> error "Unexpected null in database specific value"
-- Unsupported
go other _ _ = error $ "MySQL.getGetter: type " ++
show other ++ " not supported."
----------------------------------------------------------------------
-- | Create the migration plan for the given 'PersistEntity'
-- @val@.
migrate' :: MySQL.ConnectInfo
-> [EntityDef]
-> (Text -> IO Statement)
-> EntityDef
-> IO (Either [Text] [(Bool, Text)])
migrate' connectInfo allDefs getter val = do
let name = entityDB val
let (newcols, udefs, fdefs) = mysqlMkColumns allDefs val
old <- getColumns connectInfo getter val newcols
let udspair = map udToPair udefs
case ([], old, partitionEithers old) of
-- Nothing found, create everything
([], [], _) -> do
let uniques = do
(uname, ucols) <- udspair
pure
$ AlterTable name
$ AddUniqueConstraint uname
$ map (findTypeAndMaxLen name) ucols
let foreigns = do
Column { cName=cname, cReference=Just cRef } <- newcols
let refConstraintName = crConstraintName cRef
let refTblName = crTableName cRef
let refTarget =
addReference allDefs refConstraintName refTblName cname (crFieldCascade cRef)
guard $ refTblName /= name && cname /= fieldDB (entityId val)
return $ AlterColumn name (refTblName, refTarget)
let foreignsAlt =
map
(\fdef ->
let (childfields, parentfields) =
unzip
$ map (\((_,b),(_,d)) -> (b,d))
$ foreignFields fdef
in
AlterColumn
name
( foreignRefTableDBName fdef
, AddReference
(foreignRefTableDBName fdef)
(foreignConstraintNameDBName fdef)
childfields parentfields
(foreignFieldCascade fdef)
)
)
fdefs
return
$ Right
$ map showAlterDb
$ (addTable newcols val) : uniques ++ foreigns ++ foreignsAlt
-- No errors and something found, migrate
(_, _, ([], old')) -> do
let excludeForeignKeys (xs,ys) =
( map
(\c ->
case cReference c of
Just ColumnReference {crConstraintName=fk} ->
case find (\f -> fk == foreignConstraintNameDBName f) fdefs of
Just _ -> c { cReference = Nothing }
Nothing -> c
Nothing -> c
)
xs
, ys
)
(acs, ats) =
getAlters
allDefs
val
(newcols, udspair)
$ excludeForeignKeys
$ partitionEithers
$ old'
acs' =
map (AlterColumn name) acs
ats' =
map (AlterTable name) ats
return
$ Right
$ map showAlterDb
$ acs' ++ ats'
-- Errors
(_, _, (errs, _)) ->
return $ Left errs
where
findTypeAndMaxLen tblName col =
let (col', ty) = findTypeOfColumn allDefs tblName col
(_, ml) = findMaxLenOfColumn allDefs tblName col
in
(col', ty, ml)
addTable :: [Column] -> EntityDef -> AlterDB
addTable cols entity = AddTable $ concat
-- Lower case e: see Database.Persist.Sql.Migration
[ "CREATe TABLE "
, escapeDBName name
, "("
, idtxt
, if null nonIdCols then [] else ","
, intercalate "," $ map showColumn nonIdCols
, ")"
]
where
nonIdCols =
filter (\c -> cName c /= fieldDB (entityId entity) ) cols
name = entityDB entity
idtxt = case entityPrimary entity of
Just pdef -> concat [" PRIMARY KEY (", intercalate "," $ map (escapeDBName . fieldDB) $ compositeFields pdef, ")"]
Nothing ->
let defText = defaultAttribute $ fieldAttrs $ entityId entity
sType = fieldSqlType $ entityId entity
autoIncrementText = case (sType, defText) of
(SqlInt64, Nothing) -> " AUTO_INCREMENT"
_ -> ""
maxlen = findMaxLenOfField (entityId entity)
in concat
[ escapeDBName $ fieldDB $ entityId entity
, " " <> showSqlType sType maxlen False
, " NOT NULL"
, autoIncrementText
, " PRIMARY KEY"
]
-- | Find out the type of a column.
findTypeOfColumn :: [EntityDef] -> DBName -> DBName -> (DBName, FieldType)
findTypeOfColumn allDefs name col =
maybe
(error $ "Could not find type of column " ++
show col ++ " on table " ++ show name ++
" (allDefs = " ++ show allDefs ++ ")"
)
((,) col)
$ do
entDef <- find ((== name) . entityDB) allDefs
fieldDef <- find ((== col) . fieldDB) (entityFields entDef)
return (fieldType fieldDef)
-- | Find out the maxlen of a column (default to 200)
findMaxLenOfColumn :: [EntityDef] -> DBName -> DBName -> (DBName, Integer)
findMaxLenOfColumn allDefs name col =
maybe (col, 200)
((,) col) $ do
entDef <- find ((== name) . entityDB) allDefs
fieldDef <- find ((== col) . fieldDB) (entityFields entDef)
findMaxLenOfField fieldDef
-- | Find out the maxlen of a field
findMaxLenOfField :: FieldDef -> Maybe Integer
findMaxLenOfField fieldDef =
listToMaybe
. mapMaybe (\case
FieldAttrMaxlen x -> Just x
_ -> Nothing)
. fieldAttrs
$ fieldDef
-- | Helper for 'AddReference' that finds out the which primary key columns to reference.
addReference
:: [EntityDef]
-- ^ List of all known 'EntityDef's.
-> DBName
-- ^ Foreign key name
-> DBName
-- ^ Referenced table name
-> DBName
-- ^ Column name
-> FieldCascade
-> AlterColumn
addReference allDefs fkeyname reftable cname fc =
AddReference reftable fkeyname [cname] referencedColumns fc
where
errorMessage =
error
$ "Could not find ID of entity " ++ show reftable
++ " (allDefs = " ++ show allDefs ++ ")"
referencedColumns =
fromMaybe errorMessage $ do
entDef <- find ((== reftable) . entityDB) allDefs
return $ map fieldDB $ entityKeyFields entDef
data AlterColumn = Change Column
| Add' Column
| Drop
| Default String
| NoDefault
| Gen SqlType (Maybe Integer) String
| NoGen SqlType (Maybe Integer)
| Update' String
-- | See the definition of the 'showAlter' function to see how these fields are used.
| AddReference
DBName -- Referenced table
DBName -- Foreign key name
[DBName] -- Referencing columns
[DBName] -- Referenced columns
FieldCascade
| DropReference DBName
deriving Show
type AlterColumn' = (DBName, AlterColumn)
data AlterTable = AddUniqueConstraint DBName [(DBName, FieldType, Integer)]
| DropUniqueConstraint DBName
deriving Show
data AlterDB = AddTable String
| AlterColumn DBName AlterColumn'
| AlterTable DBName AlterTable
deriving Show
udToPair :: UniqueDef -> (DBName, [DBName])
udToPair ud = (uniqueDBName ud, map snd $ uniqueFields ud)
----------------------------------------------------------------------
-- | Returns all of the 'Column'@s@ in the given table currently
-- in the database.
getColumns
:: HasCallStack
=> MySQL.ConnectInfo
-> (Text -> IO Statement)
-> EntityDef -> [Column]
-> IO [Either Text (Either Column (DBName, [DBName]))]
getColumns connectInfo getter def cols = do
-- Find out all columns.
stmtClmns <- getter $ T.concat
[ "SELECT COLUMN_NAME, "
, "IS_NULLABLE, "
, "DATA_TYPE, "
, "COLUMN_TYPE, "
, "CHARACTER_MAXIMUM_LENGTH, "
, "NUMERIC_PRECISION, "
, "NUMERIC_SCALE, "
, "COLUMN_DEFAULT, "
, "GENERATION_EXPRESSION "
, "FROM INFORMATION_SCHEMA.COLUMNS "
, "WHERE TABLE_SCHEMA = ? "
, "AND TABLE_NAME = ? "
-- , "AND COLUMN_NAME <> ?"
]
inter2 <- with (stmtQuery stmtClmns vals) (\src -> runConduitRes $ src .| CL.consume)
cs <- runConduitRes $ CL.sourceList inter2 .| helperClmns -- avoid nested queries
-- Find out the constraints.
stmtCntrs <- getter $ T.concat
[ "SELECT CONSTRAINT_NAME, "
, "COLUMN_NAME "
, "FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE "
, "WHERE TABLE_SCHEMA = ? "
, "AND TABLE_NAME = ? "
-- , "AND COLUMN_NAME <> ? "
, "AND CONSTRAINT_NAME <> 'PRIMARY' "
, "AND REFERENCED_TABLE_SCHEMA IS NULL "
, "ORDER BY CONSTRAINT_NAME, "
, "COLUMN_NAME"
]
us <- with (stmtQuery stmtCntrs vals) (\src -> runConduitRes $ src .| helperCntrs)
-- Return both
return (cs ++ us)
where
refMap = Map.fromList $ foldl ref [] cols
where ref rs c = case cReference c of
Nothing -> rs
(Just r) -> (unDBName $ cName c, r) : rs
vals = [ PersistText $ pack $ MySQL.connectDatabase connectInfo
, PersistText $ unDBName $ entityDB def
-- , PersistText $ unDBName $ fieldDB $ entityId def
]
helperClmns = CL.mapM getIt .| CL.consume
where
getIt row = fmap (either Left (Right . Left)) .
liftIO .
getColumn connectInfo getter (entityDB def) row $ ref
where ref = case row of
(PersistText cname : _) -> (Map.lookup cname refMap)
_ -> Nothing
helperCntrs = do
let check [ PersistText cntrName
, PersistText clmnName] = return ( cntrName, clmnName )
check other = fail $ "helperCntrs: unexpected " ++ show other
rows <- mapM check =<< CL.consume
return $ map (Right . Right . (DBName . fst . head &&& map (DBName . snd)))
$ groupBy ((==) `on` fst) rows
-- | Get the information about a column in a table.
getColumn
:: HasCallStack
=> MySQL.ConnectInfo
-> (Text -> IO Statement)
-> DBName
-> [PersistValue]
-> Maybe ColumnReference
-> IO (Either Text Column)
getColumn connectInfo getter tname [ PersistText cname
, PersistText null_
, PersistText dataType
, PersistText colType
, colMaxLen
, colPrecision
, colScale
, default'
, generated
] cRef =
fmap (either (Left . pack) Right) $
runExceptT $ do
-- Default value
default_ <-
case default' of
PersistNull -> return Nothing
PersistText t -> return (Just t)
PersistByteString bs ->
case T.decodeUtf8' bs of
Left exc ->
fail
$ "Invalid default column: "
++ show default'
++ " (error: " ++ show exc ++ ")"
Right t ->
return (Just t)
_ ->
fail $ "Invalid default column: " ++ show default'
generated_ <-
case generated of
PersistNull -> return Nothing
PersistText "" -> return Nothing
PersistByteString "" -> return Nothing
PersistText t -> return (Just t)
PersistByteString bs ->
case T.decodeUtf8' bs of
Left exc ->
fail
$ "Invalid generated column: "
++ show generated
++ " (error: " ++ show exc ++ ")"
Right t ->
return (Just t)
_ ->
fail $ "Invalid generated column: " ++ show generated
ref <- getRef (crConstraintName <$> cRef)
let colMaxLen' =
case colMaxLen of
PersistInt64 l -> Just (fromIntegral l)
_ -> Nothing
ci = ColumnInfo
{ ciColumnType = colType
, ciMaxLength = colMaxLen'
, ciNumericPrecision = colPrecision
, ciNumericScale = colScale
}
(typ, maxLen) <- parseColumnType dataType ci
-- Okay!
return Column
{ cName = DBName $ cname
, cNull = null_ == "YES"
, cSqlType = typ
, cDefault = default_
, cGenerated = generated_
, cDefaultConstraintName = Nothing
, cMaxLen = maxLen
, cReference = ref
}
where
getRef Nothing = return Nothing
getRef (Just refName') = do
-- Foreign key (if any)
stmt <- lift . getter $ T.concat
[ "SELECT KCU.REFERENCED_TABLE_NAME, "
, "KCU.CONSTRAINT_NAME, "
, "KCU.ORDINAL_POSITION, "
, "DELETE_RULE, "
, "UPDATE_RULE "
, "FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU "
, "INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC "
, " ON KCU.CONSTRAINT_NAME = RC.CONSTRAINT_NAME "
, "WHERE KCU.TABLE_SCHEMA = ? "
, "AND KCU.TABLE_NAME = ? "
, "AND KCU.COLUMN_NAME = ? "
, "AND KCU.REFERENCED_TABLE_SCHEMA = ? "
, "AND KCU.CONSTRAINT_NAME = ? "
, "ORDER BY KCU.CONSTRAINT_NAME, "
, "KCU.COLUMN_NAME"
]
let vars =
[ PersistText $ pack $ MySQL.connectDatabase connectInfo
, PersistText $ unDBName $ tname
, PersistText cname
, PersistText $ pack $ MySQL.connectDatabase connectInfo
, PersistText $ unDBName refName'
]
parseCascadeAction txt =
case txt of
"RESTRICT" -> Just Restrict
"CASCADE" -> Just Cascade
"SET NULL" -> Just SetNull
"SET DEFAULT" -> Just SetDefault
"NO ACTION" -> Nothing
_ ->
error $ "Unexpected value in parseCascadeAction: " <> show txt
cntrs <- liftIO $ with (stmtQuery stmt vars) (\src -> runConduit $ src .| CL.consume)
pure $ case cntrs of
[] ->
Nothing
[[PersistText tab, PersistText ref, PersistInt64 pos, PersistText onDel, PersistText onUpd]] ->
if pos == 1
then Just $ ColumnReference (DBName tab) (DBName ref) FieldCascade
{ fcOnUpdate = parseCascadeAction onUpd
, fcOnDelete = parseCascadeAction onDel
}
else Nothing
xs -> error $ mconcat
[ "MySQL.getColumn/getRef: error fetching constraints. Expected a single result for foreign key query for table: "
, T.unpack (unDBName tname)
, " and column: "
, T.unpack cname
, " but got: "
, show xs
]
getColumn _ _ _ x _ =
return $ Left $ pack $ "Invalid result from INFORMATION_SCHEMA: " ++ show x
-- | Extra column information from MySQL schema
data ColumnInfo = ColumnInfo
{ ciColumnType :: Text
, ciMaxLength :: Maybe Integer
, ciNumericPrecision :: PersistValue
, ciNumericScale :: PersistValue
}
-- | Parse the type of column as returned by MySQL's
-- @INFORMATION_SCHEMA@ tables.
parseColumnType :: Text -> ColumnInfo -> ExceptT String IO (SqlType, Maybe Integer)
-- Ints
parseColumnType "tinyint" ci | ciColumnType ci == "tinyint(1)" = return (SqlBool, Nothing)
parseColumnType "int" ci | ciColumnType ci == "int(11)" = return (SqlInt32, Nothing)
parseColumnType "bigint" ci | ciColumnType ci == "bigint(20)" = return (SqlInt64, Nothing)
-- Double
parseColumnType x@("double") ci | ciColumnType ci == x = return (SqlReal, Nothing)
parseColumnType "decimal" ci =
case (ciNumericPrecision ci, ciNumericScale ci) of
(PersistInt64 p, PersistInt64 s) ->
return (SqlNumeric (fromIntegral p) (fromIntegral s), Nothing)
_ ->
fail "missing DECIMAL precision in DB schema"
-- Text
parseColumnType "varchar" ci = return (SqlString, ciMaxLength ci)
parseColumnType "text" _ = return (SqlString, Nothing)
-- ByteString
parseColumnType "varbinary" ci = return (SqlBlob, ciMaxLength ci)
parseColumnType "blob" _ = return (SqlBlob, Nothing)
-- Time-related
parseColumnType "time" _ = return (SqlTime, Nothing)
parseColumnType "datetime" _ = return (SqlDayTime, Nothing)
parseColumnType "date" _ = return (SqlDay, Nothing)
parseColumnType _ ci = return (SqlOther (ciColumnType ci), Nothing)
----------------------------------------------------------------------
-- | @getAlters allDefs tblName new old@ finds out what needs to
-- be changed from @old@ to become @new@.
getAlters
:: [EntityDef]
-> EntityDef
-> ([Column], [(DBName, [DBName])])
-> ([Column], [(DBName, [DBName])])
-> ([AlterColumn'], [AlterTable])
getAlters allDefs edef (c1, u1) (c2, u2) =
(getAltersC c1 c2, getAltersU u1 u2)
where
tblName = entityDB edef
getAltersC [] old = concatMap dropColumn old
getAltersC (new:news) old =
let (alters, old') = findAlters edef allDefs new old
in alters ++ getAltersC news old'
dropColumn col =
map ((,) (cName col)) $
[DropReference (crConstraintName cr) | Just cr <- [cReference col]] ++
[Drop]
getAltersU [] old = map (DropUniqueConstraint . fst) old
getAltersU ((name, cols):news) old =
case lookup name old of
Nothing ->
AddUniqueConstraint name (map findTypeAndMaxLen cols)
: getAltersU news old
Just ocols ->
let old' = filter (\(x, _) -> x /= name) old
in if sort cols == ocols
then getAltersU news old'
else DropUniqueConstraint name
: AddUniqueConstraint name (map findTypeAndMaxLen cols)
: getAltersU news old'
where
findTypeAndMaxLen col =
let (col', ty) = findTypeOfColumn allDefs tblName col
(_, ml) = findMaxLenOfColumn allDefs tblName col
in
(col', ty, ml)
-- | @findAlters x y newColumn oldColumns@ finds out what needs to be
-- changed in the columns @oldColumns@ for @newColumn@ to be
-- supported.
findAlters
:: EntityDef
-> [EntityDef]
-> Column
-> [Column]
-> ([AlterColumn'], [Column])
findAlters edef allDefs col@(Column name isNull type_ def gen _defConstraintName maxLen ref) cols =
case filter ((name ==) . cName) cols of
-- new fkey that didn't exist before
[] ->
case ref of
Nothing -> ([(name, Add' col)],[])
Just cr ->
let tname = crTableName cr
cname = crConstraintName cr
cnstr = [addReference allDefs cname tname name (crFieldCascade cr)]
in
(map ((,) tname) (Add' col : cnstr), cols)
Column _ isNull' type_' def' gen' _defConstraintName' maxLen' ref' : _ ->
let -- Foreign key
refDrop =
case (ref == ref', ref') of
(False, Just ColumnReference {crConstraintName=cname}) ->
[(name, DropReference cname)]
_ ->
[]
refAdd =
case (ref == ref', ref) of
(False, Just ColumnReference {crTableName=tname, crConstraintName=cname, crFieldCascade = cfc })
| tname /= entityDB edef
, cname /= fieldDB (entityId edef)
->
[(tname, addReference allDefs cname tname name cfc)]
_ -> []
-- Type and nullability
modType | showSqlType type_ maxLen False `ciEquals` showSqlType type_' maxLen' False && isNull == isNull' = []
| otherwise = [(name, Change col)]
-- Default value
-- Avoid DEFAULT NULL, since it is always unnecessary, and is an error for text/blob fields
modDef =
if def == def' then []
else case def of
Nothing -> [(name, NoDefault)]
Just s ->
if T.toUpper s == "NULL" then []
else [(name, Default $ T.unpack s)]
-- Does the generated value need to change?
modGen =
if gen == gen' then []
else case gen of
Nothing -> [(name, NoGen type_ maxLen)]
Just genExpr -> [(name, Gen type_ maxLen $ T.unpack genExpr)]
in ( refDrop ++ modType ++ modDef ++ modGen ++ refAdd
, filter ((name /=) . cName) cols
)
where
ciEquals x y = T.toCaseFold (T.pack x) == T.toCaseFold (T.pack y)
----------------------------------------------------------------------
-- | Prints the part of a @CREATE TABLE@ statement about a given
-- column.
showColumn :: Column -> String
showColumn (Column n nu t def gen _defConstraintName maxLen ref) = concat
[ escapeDBName n
, " "
, showSqlType t maxLen True
, " "
, case gen of
Nothing -> ""
Just genExpr ->
if T.toUpper genExpr == "NULL" then ""
else " GENERATED ALWAYS AS (" <> T.unpack genExpr <> ") STORED "
, if nu then "NULL" else "NOT NULL"
, case def of
Nothing -> ""
Just s -> -- Avoid DEFAULT NULL, since it is always unnecessary, and is an error for text/blob fields
if T.toUpper s == "NULL" then ""
else " DEFAULT " ++ T.unpack s
, case ref of
Nothing -> ""
Just cRef -> " REFERENCES " ++ escapeDBName (crTableName cRef)
<> " " <> T.unpack (renderFieldCascade (crFieldCascade cRef))
]
-- | Renders an 'SqlType' in MySQL's format.
showSqlType :: SqlType
-> Maybe Integer -- ^ @maxlen@
-> Bool -- ^ include character set information?
-> String
showSqlType SqlBlob Nothing _ = "BLOB"
showSqlType SqlBlob (Just i) _ = "VARBINARY(" ++ show i ++ ")"
showSqlType SqlBool _ _ = "TINYINT(1)"
showSqlType SqlDay _ _ = "DATE"
showSqlType SqlDayTime _ _ = "DATETIME"
showSqlType SqlInt32 _ _ = "INT(11)"
showSqlType SqlInt64 _ _ = "BIGINT"
showSqlType SqlReal _ _ = "DOUBLE"
showSqlType (SqlNumeric s prec) _ _ = "NUMERIC(" ++ show s ++ "," ++ show prec ++ ")"
showSqlType SqlString Nothing True = "TEXT CHARACTER SET utf8mb4"
showSqlType SqlString Nothing False = "TEXT"
showSqlType SqlString (Just i) True = "VARCHAR(" ++ show i ++ ") CHARACTER SET utf8mb4"
showSqlType SqlString (Just i) False = "VARCHAR(" ++ show i ++ ")"
showSqlType SqlTime _ _ = "TIME"
showSqlType (SqlOther t) _ _ = T.unpack t
-- | Render an action that must be done on the database.
showAlterDb :: AlterDB -> (Bool, Text)
showAlterDb (AddTable s) = (False, pack s)
showAlterDb (AlterColumn t (c, ac)) =
(isUnsafe ac, pack $ showAlter t (c, ac))
where
isUnsafe Drop = True
isUnsafe _ = False
showAlterDb (AlterTable t at) = (False, pack $ showAlterTable t at)
-- | Render an action that must be done on a table.
showAlterTable :: DBName -> AlterTable -> String
showAlterTable table (AddUniqueConstraint cname cols) = concat
[ "ALTER TABLE "
, escapeDBName table
, " ADD CONSTRAINT "
, escapeDBName cname
, " UNIQUE("
, intercalate "," $ map escapeDBName' cols
, ")"
]
where
escapeDBName' (name, (FTTypeCon _ "Text" ), maxlen) = escapeDBName name ++ "(" ++ show maxlen ++ ")"
escapeDBName' (name, (FTTypeCon _ "String" ), maxlen) = escapeDBName name ++ "(" ++ show maxlen ++ ")"
escapeDBName' (name, (FTTypeCon _ "ByteString"), maxlen) = escapeDBName name ++ "(" ++ show maxlen ++ ")"
escapeDBName' (name, _ , _) = escapeDBName name
showAlterTable table (DropUniqueConstraint cname) = concat
[ "ALTER TABLE "
, escapeDBName table
, " DROP INDEX "
, escapeDBName cname
]
-- | Render an action that must be done on a column.
showAlter :: DBName -> AlterColumn' -> String
showAlter table (oldName, Change (Column n nu t def gen defConstraintName maxLen _ref)) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " CHANGE "
, escapeDBName oldName
, " "
, showColumn (Column n nu t def gen defConstraintName maxLen Nothing)
]
showAlter table (_, Add' col) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " ADD COLUMN "
, showColumn col
]
showAlter table (n, Drop) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " DROP COLUMN "
, escapeDBName n
]
showAlter table (n, Default s) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " ALTER COLUMN "
, escapeDBName n
, " SET DEFAULT "
, s
]
showAlter table (n, NoDefault) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " ALTER COLUMN "
, escapeDBName n
, " DROP DEFAULT"
]
showAlter table (col, Gen typ len expr) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " MODIFY COLUMN "
, escapeDBName col
, " "
, showSqlType typ len True
, " GENERATED ALWAYS AS ("
, expr
, ") STORED"
]
showAlter table (col, NoGen typ len) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " MODIFY COLUMN "
, escapeDBName col
, " "
, showSqlType typ len True
]
showAlter table (n, Update' s) =
concat
[ "UPDATE "
, escapeDBName table
, " SET "
, escapeDBName n
, "="
, s
, " WHERE "
, escapeDBName n
, " IS NULL"
]
showAlter table (_, AddReference reftable fkeyname t2 id2 fc) = concat
[ "ALTER TABLE "
, escapeDBName table
, " ADD CONSTRAINT "
, escapeDBName fkeyname
, " FOREIGN KEY("
, intercalate "," $ map escapeDBName t2
, ") REFERENCES "
, escapeDBName reftable
, "("
, intercalate "," $ map escapeDBName id2
, ") "
, T.unpack $ renderFieldCascade fc
]
showAlter table (_, DropReference cname) = concat
[ "ALTER TABLE "
, escapeDBName table
, " DROP FOREIGN KEY "
, escapeDBName cname
]
----------------------------------------------------------------------
escape :: DBName -> Text
escape = T.pack . escapeDBName
-- | Escape a database name to be included on a query.
escapeDBName :: DBName -> String
escapeDBName (DBName s) = '`' : go (T.unpack s)
where
go ('`':xs) = '`' : '`' : go xs
go ( x :xs) = x : go xs
go "" = "`"
-- | Information required to connect to a MySQL database
-- using @persistent@'s generic facilities. These values are the
-- same that are given to 'withMySQLPool'.
data MySQLConf = MySQLConf
{ myConnInfo :: MySQL.ConnectInfo
-- ^ The connection information.
, myPoolSize :: Int
-- ^ How many connections should be held on the connection pool.
} deriving Show
instance FromJSON MySQLConf where
parseJSON v = modifyFailure ("Persistent: error loading MySQL conf: " ++) $
flip (withObject "MySQLConf") v $ \o -> do
database <- o .: "database"
host <- o .: "host"
port <- o .: "port"
path <- o .:? "path"
user <- o .: "user"
password <- o .: "password"
pool <- o .: "poolsize"
let ci = MySQL.defaultConnectInfo
{ MySQL.connectHost = host
, MySQL.connectPort = port
, MySQL.connectPath = case path of
Just p -> p
Nothing -> MySQL.connectPath MySQL.defaultConnectInfo
, MySQL.connectUser = user
, MySQL.connectPassword = password
, MySQL.connectDatabase = database
}
return $ MySQLConf ci pool
instance PersistConfig MySQLConf where
type PersistConfigBackend MySQLConf = SqlPersistT
type PersistConfigPool MySQLConf = ConnectionPool
createPoolConfig (MySQLConf cs size) = runNoLoggingT $ createMySQLPool cs size -- FIXME
runPool _ = runSqlPool
loadConfig = parseJSON
applyEnv conf = do
env <- getEnvironment
let maybeEnv old var = maybe old id $ lookup ("MYSQL_" ++ var) env
return conf
{ myConnInfo =
case myConnInfo conf of
MySQL.ConnectInfo
{ MySQL.connectHost = host
, MySQL.connectPort = port
, MySQL.connectPath = path
, MySQL.connectUser = user
, MySQL.connectPassword = password
, MySQL.connectDatabase = database
} -> (myConnInfo conf)
{ MySQL.connectHost = maybeEnv host "HOST"
, MySQL.connectPort = read $ maybeEnv (show port) "PORT"
, MySQL.connectPath = maybeEnv path "PATH"
, MySQL.connectUser = maybeEnv user "USER"
, MySQL.connectPassword = maybeEnv password "PASSWORD"
, MySQL.connectDatabase = maybeEnv database "DATABASE"
}
}
mockMigrate :: MySQL.ConnectInfo
-> [EntityDef]
-> (Text -> IO Statement)
-> EntityDef
-> IO (Either [Text] [(Bool, Text)])
mockMigrate _connectInfo allDefs _getter val = do
let name = entityDB val
let (newcols, udefs, fdefs) = mysqlMkColumns allDefs val
let udspair = map udToPair udefs
case () of
-- Nothing found, create everything
() -> do
let uniques = flip concatMap udspair $ \(uname, ucols) ->
[ AlterTable name $
AddUniqueConstraint uname $
map (findTypeAndMaxLen name) ucols ]
let foreigns = do
Column { cName=cname, cReference= Just ColumnReference{crTableName = refTable, crConstraintName = refConstr, crFieldCascade = cfc }} <- newcols
return $ AlterColumn name (refTable, addReference allDefs refConstr refTable cname cfc)
let foreignsAlt =
map
(\fdef ->
let (childfields, parentfields) = unzip (map (\((_,b),(_,d)) -> (b,d)) (foreignFields fdef))
in
AlterColumn
name
( foreignRefTableDBName fdef
, AddReference
(foreignRefTableDBName fdef)
(foreignConstraintNameDBName fdef)
childfields
parentfields
(foreignFieldCascade fdef)
)
)
fdefs
return $ Right $ map showAlterDb $ (addTable newcols val): uniques ++ foreigns ++ foreignsAlt
where
findTypeAndMaxLen tblName col = let (col', ty) = findTypeOfColumn allDefs tblName col
(_, ml) = findMaxLenOfColumn allDefs tblName col
in (col', ty, ml)
-- | Mock a migration even when the database is not present.
-- This function will mock the migration for a database even when
-- the actual database isn't already present in the system.
mockMigration :: Migration -> IO ()
mockMigration mig = do
smap <- newIORef $ Map.empty
let sqlbackend = SqlBackend { connPrepare = \_ -> do
return Statement
{ stmtFinalize = return ()
, stmtReset = return ()
, stmtExecute = undefined
, stmtQuery = \_ -> return $ return ()
},
connInsertManySql = Nothing,
connInsertSql = undefined,
connStmtMap = smap,
connClose = undefined,
connMigrateSql = mockMigrate undefined,
connBegin = undefined,
connCommit = undefined,
connRollback = undefined,
connEscapeName = undefined,
connNoLimit = undefined,
connRDBMS = undefined,
connLimitOffset = undefined,
connLogFunc = undefined,
connUpsertSql = undefined,
connPutManySql = undefined,
connMaxParams = Nothing,
connRepsertManySql = Nothing
}
result = runReaderT . runWriterT . runWriterT $ mig
resp <- result sqlbackend
mapM_ T.putStrLn $ map snd $ snd resp
-- | MySQL specific 'upsert_'. This will prevent multiple queries, when one will
-- do. The record will be inserted into the database. In the event that the
-- record already exists in the database, the record will have the
-- relevant updates performed.
insertOnDuplicateKeyUpdate
:: ( backend ~ PersistEntityBackend record
, PersistEntity record
, MonadIO m
, PersistStore backend
, BackendCompatible SqlBackend backend
)
=> record
-> [Update record]
-> ReaderT backend m ()
insertOnDuplicateKeyUpdate record =
insertManyOnDuplicateKeyUpdate [record] []
-- | This type is used to determine how to update rows using MySQL's
-- @INSERT ... ON DUPLICATE KEY UPDATE@ functionality, exposed via
-- 'insertManyOnDuplicateKeyUpdate' in this library.
--
-- @since 2.8.0
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
-- | An alias for 'HandleUpdateCollision'. The type previously was only
-- used to copy a single value, but was expanded to be handle more complex
-- queries.
--
-- @since 2.6.2
type SomeField = HandleUpdateCollision
pattern SomeField :: EntityField record typ -> SomeField record
pattern SomeField x = CopyField x
{-# DEPRECATED SomeField "The type SomeField is deprecated. Use the type HandleUpdateCollision instead, and use the function copyField instead of the data constructor." #-}
-- | Copy the field into the database only if the value in the
-- corresponding record is non-@NULL@.
--
-- @since 2.6.2
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
-- 'insertManyOnDuplicateKeyUpdate' function.
--
-- @since 2.6.2
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
-- 'insertManyOnDuplicateKeyUpdate' function.
--
-- @since 2.6.2
copyUnlessEq :: PersistField typ => EntityField record typ -> typ -> HandleUpdateCollision record
copyUnlessEq = CopyUnlessEq
-- | Copy the field directly from the record.
--
-- @since 3.0
copyField :: PersistField typ => EntityField record typ -> HandleUpdateCollision record
copyField = CopyField
-- | Do a bulk insert on the given records in the first parameter. In the event
-- that a key conflicts with a record currently in the database, the second and
-- third parameters determine what will happen.
--
-- The second parameter is a list of fields to copy from the original value.
-- This allows you to specify which fields to copy from the record you're trying
-- to insert into the database to the preexisting row.
--
-- The third parameter is a list of updates to perform that are independent of
-- the value that is provided. You can use this to increment a counter value.
-- These updates only occur if the original record is present in the database.
--
-- === __More details on 'HandleUpdateCollision' usage__
--
-- The @['HandleUpdateCollision']@ parameter allows you to specify which fields (and
-- under which conditions) will be copied from the inserted rows. For
-- a brief example, consider the following data model and existing data set:
--
-- @
-- Item
-- name Text
-- description Text
-- price Double Maybe
-- quantity Int Maybe
--
-- Primary name
-- @
--
-- > items:
-- > +------+-------------+-------+----------+
-- > | name | description | price | quantity |
-- > +------+-------------+-------+----------+
-- > | foo | very good | | 3 |
-- > | bar | | 3.99 | |
-- > +------+-------------+-------+----------+
--
-- This record type has a single natural key on @itemName@. Let's suppose
-- that we download a CSV of new items to store into the database. Here's
-- our CSV:
--
-- > name,description,price,quantity
-- > foo,,2.50,6
-- > bar,even better,,5
-- > yes,wow,,
--
-- We parse that into a list of Haskell records:
--
-- @
-- records =
-- [ Item { itemName = "foo", itemDescription = ""
-- , itemPrice = Just 2.50, itemQuantity = Just 6
-- }
-- , Item "bar" "even better" Nothing (Just 5)
-- , Item "yes" "wow" Nothing Nothing
-- ]
-- @
--
-- The new CSV data is partial. It only includes __updates__ from the
-- upstream vendor. Our CSV library parses the missing description field as
-- an empty string. We don't want to override the existing description. So
-- we can use the 'copyUnlessEmpty' function to say: "Don't update when the
-- value is empty."
--
-- Likewise, the new row for @bar@ includes a quantity, but no price. We do
-- not want to overwrite the existing price in the database with a @NULL@
-- value. So we can use 'copyUnlessNull' to only copy the existing values
-- in.
--
-- The final code looks like this:
-- @
-- 'insertManyOnDuplicateKeyUpdate' records
-- [ 'copyUnlessEmpty' ItemDescription
-- , 'copyUnlessNull' ItemPrice
-- , 'copyUnlessNull' ItemQuantity
-- ]
-- []
-- @
--
-- Once we run that code on the datahase, the new data set looks like this:
--
-- > items:
-- > +------+-------------+-------+----------+
-- > | name | description | price | quantity |
-- > +------+-------------+-------+----------+
-- > | foo | very good | 2.50 | 6 |
-- > | bar | even better | 3.99 | 5 |
-- > | yes | wow | | |
-- > +------+-------------+-------+----------+
insertManyOnDuplicateKeyUpdate
:: forall record backend m.
( backend ~ PersistEntityBackend record
, BackendCompatible SqlBackend backend
, PersistEntity 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.
-> ReaderT backend m ()
insertManyOnDuplicateKeyUpdate [] _ _ = return ()
insertManyOnDuplicateKeyUpdate records fieldValues updates =
uncurry rawExecute
$ mkBulkInsertQuery records fieldValues updates
-- | This creates the query for 'bulkInsertOnDuplicateKeyUpdate'. 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.
mkBulkInsertQuery
:: PersistEntity record
=> [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.
-> (Text, [PersistValue])
mkBulkInsertQuery records fieldValues updates =
(q, recordValues <> updsValues <> copyUnlessValues)
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 = T.pack . escapeDBName . fieldDB
entityDef' = entityDef records
firstField = case entityFieldNames of
[] -> error "The entity you're trying to insert does not have any fields."
(field:_) -> field
entityFieldNames = map fieldDbToText (entityFields entityDef')
tableName = T.pack . escapeDBName . entityDB $ 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("
, "VALUES(", n, "),"
, "?"
, "),"
, n
, ")"
]
condFieldSets = map (uncurry mkCondFieldSet) fieldsToMaybeCopy
fieldSets = map (\n -> T.concat [n, "=VALUES(", n, ")"]) updateFieldNames
upds = map (Util.mkUpdateText' (pack . escapeDBName) id) updates
updsValues = map (\(Update _ val _) -> toPersistValue val) updates
updateText = case fieldSets <> upds <> condFieldSets of
[] -> T.concat [firstField, "=", firstField]
xs -> Util.commaSeparated xs
q = T.concat
[ "INSERT INTO "
, tableName
, " ("
, Util.commaSeparated entityFieldNames
, ") "
, " VALUES "
, recordPlaceholders
, " ON DUPLICATE KEY UPDATE "
, updateText
]
putManySql :: EntityDef -> Int -> Text
putManySql ent n = putManySql' fields ent n
where
fields = entityFields ent
repsertManySql :: EntityDef -> Int -> Text
repsertManySql ent n = putManySql' fields ent n
where
fields = keyAndEntityFields ent
putManySql' :: [FieldDef] -> EntityDef -> Int -> Text
putManySql' (filter isFieldNotGenerated -> fields) ent n = q
where
fieldDbToText = escape . fieldDB
mkAssignment f = T.concat [f, "=VALUES(", f, ")"]
table = escape . entityDB $ 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 DUPLICATE KEY UPDATE "
, Util.commaSeparated updates
]
mysqlMkColumns :: [EntityDef] -> EntityDef -> ([Column], [UniqueDef], [ForeignDef])
mysqlMkColumns allDefs t = mkColumns allDefs t emptyBackendSpecificOverrides