{-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE FlexibleContexts #-} -- | 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(..) ) where import Control.Arrow import Control.Monad (mzero) import Control.Monad.IO.Class (MonadIO (..)) import Control.Monad.Trans.Class (lift) import Control.Monad.Trans.Error (ErrorT(..)) import Data.Aeson import Data.ByteString (ByteString) import Data.Either (partitionEithers) import Data.Fixed (Pico) import Data.Function (on) import Data.IORef import Data.List (find, intercalate, sort, groupBy) import Data.Text (Text, pack) import System.Environment (getEnvironment) import Data.Conduit import qualified Blaze.ByteString.Builder.Char8 as BBB import qualified Blaze.ByteString.Builder.ByteString as BBS import qualified Data.Conduit.List as CL import qualified Data.Map as Map import qualified Data.Text as T import qualified Data.Text.Encoding as T import Database.Persist.Sql import Data.Int (Int64) 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 import qualified Database.MySQL.Base as MySQLBase import qualified Database.MySQL.Base.Types as MySQLBase -- | 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 :: MonadIO m => MySQL.ConnectInfo -- ^ Connection information. -> Int -- ^ Number of connections to be kept open in the pool. -> (ConnectionPool -> 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 -- responsability to properly close the connection pool when -- unneeded. Use 'withMySQLPool' for automatic resource control. createMySQLPool :: MonadIO m => MySQL.ConnectInfo -- ^ Connection information. -> Int -- ^ Number of connections to be kept open in the pool. -> m ConnectionPool createMySQLPool ci = createSqlPool $ open' ci -- | Same as 'withMySQLPool', but instead of opening a pool -- of connections, only one connection is opened. withMySQLConn :: (MonadBaseControl IO m, MonadIO m) => MySQL.ConnectInfo -- ^ Connection information. -> (Connection -> 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 -> IO Connection open' ci = do conn <- MySQL.connect ci MySQLBase.autocommit conn False -- disable autocommit! smap <- newIORef $ Map.empty return Connection { connPrepare = prepare' conn , connStmtMap = smap , connInsertSql = insertSql' , connClose = MySQL.close conn , connMigrateSql = migrate' ci , connBegin = const $ 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 -- , connRDBMS = "mysql" , connLimitOffset = decorateSQLWithLimitOffset "LIMIT 18446744073709551615" } -- | 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 SqlType -> [PersistValue] -> InsertSqlResult insertSql' ent vals = let sql = pack $ concat [ "INSERT INTO " , escapeDBName $ entityDB ent , "(" , intercalate "," $ map (escapeDBName . fieldDB) $ entityFields ent , ") VALUES(" , intercalate "," (map (const "?") $ entityFields ent) , ")" ] in case entityPrimary ent of Just _ -> ISRManyKeys sql vals Nothing -> ISRInsertGet sql "SELECT LAST_INSERT_ID()" -- | 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' :: MonadResource m => MySQL.Connection -> MySQL.Query -> [PersistValue] -> Source m [PersistValue] withStmt' conn query vals = bracketP createResult MySQLBase.freeResult fetchRows >>= 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 (MySQLBase.fieldType f) f . Just) | f <- fields] convert = use getters where use (g:gs) (col:cols) = let v = g col vs = use gs cols in v `seq` vs `seq` (v:vs) use _ _ = [] -- Ready to go! let go acc = do row <- MySQLBase.fetchRow result case row of [] -> return (acc []) _ -> let converted = convert row in converted `seq` 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 (PersistZonedTime (ZT t))) = MySQL.render $ show 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 Ambigous, can not select precision without information about field render (P (PersistDbSpecific s)) = MySQL.Plain $ BBS.fromByteString s 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.Type -> Getter PersistValue -- Bool getGetter MySQLBase.Tiny = convertPV PersistBool -- Int64 getGetter MySQLBase.Int24 = convertPV PersistInt64 getGetter MySQLBase.Short = convertPV PersistInt64 getGetter MySQLBase.Long = convertPV PersistInt64 getGetter MySQLBase.LongLong = convertPV PersistInt64 -- Double getGetter MySQLBase.Float = convertPV PersistDouble getGetter MySQLBase.Double = convertPV PersistDouble getGetter MySQLBase.Decimal = convertPV PersistDouble getGetter MySQLBase.NewDecimal = convertPV PersistDouble -- ByteString and Text getGetter MySQLBase.VarChar = convertPV PersistByteString getGetter MySQLBase.VarString = convertPV PersistByteString getGetter MySQLBase.String = convertPV PersistByteString getGetter MySQLBase.Blob = convertPV PersistByteString getGetter MySQLBase.TinyBlob = convertPV PersistByteString getGetter MySQLBase.MediumBlob = convertPV PersistByteString getGetter MySQLBase.LongBlob = convertPV PersistByteString -- Time-related getGetter MySQLBase.Time = convertPV PersistTimeOfDay getGetter MySQLBase.DateTime = convertPV PersistUTCTime getGetter MySQLBase.Timestamp = convertPV PersistUTCTime getGetter MySQLBase.Date = convertPV PersistDay getGetter MySQLBase.NewDate = convertPV PersistDay getGetter MySQLBase.Year = convertPV PersistDay -- Null getGetter MySQLBase.Null = \_ _ -> PersistNull -- Controversial conversions getGetter MySQLBase.Set = convertPV PersistText getGetter MySQLBase.Enum = convertPV PersistText -- Conversion using PersistDbSpecific getGetter MySQLBase.Geometry = \_ m -> case m of Just g -> PersistDbSpecific g Nothing -> error "Unexpected null in database specific value" -- Unsupported getGetter other = error $ "MySQL.getGetter: type " ++ show other ++ " not supported." ---------------------------------------------------------------------- -- | Create the migration plan for the given 'PersistEntity' -- @val@. migrate' :: Show a => MySQL.ConnectInfo -> [EntityDef a] -> (Text -> IO Statement) -> EntityDef SqlType -> IO (Either [Text] [(Bool, Text)]) migrate' connectInfo allDefs getter val = do let name = entityDB val (idClmn, old) <- getColumns connectInfo getter val let (newcols, udefs, fdefs) = mkColumns allDefs val let udspair = map udToPair udefs case (idClmn, old, partitionEithers old) of -- Nothing found, create everything ([], [], _) -> do let idtxt = case entityPrimary val of Just pdef -> concat [" PRIMARY KEY (", intercalate "," $ map (escapeDBName . snd) $ primaryFields pdef, ")"] Nothing -> concat [escapeDBName $ entityID val, " BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY"] let addTable = AddTable $ concat -- Lower case e: see Database.Persist.Sql.Migration [ "CREATe TABLE " , escapeDBName name , "(" , idtxt , if null newcols then [] else "," , intercalate "," $ map showColumn newcols , ")" ] let uniques = flip concatMap udspair $ \(uname, ucols) -> [ AlterTable name $ AddUniqueConstraint uname $ map (findTypeOfColumn allDefs name) ucols ] let foreigns = do Column { cName=cname, cReference=Just (refTblName, a) } <- newcols return $ AlterColumn name (refTblName, addReference allDefs (refName name cname) refTblName cname) 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)) fdefs return $ Right $ map showAlterDb $ addTable : uniques ++ foreigns ++ foreignsAlt -- No errors and something found, migrate (_, _, ([], old')) -> do let excludeForeignKeys (xs,ys) = (map (\c -> case cReference c of Just (_,fk) -> case find (\f -> fk == foreignConstraintNameDBName f) fdefs of Just _ -> c { cReference = Nothing } Nothing -> c Nothing -> c) xs,ys) (acs, ats) = getAlters allDefs name (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 -- | Find out the type of a column. findTypeOfColumn :: Show a => [EntityDef a] -> 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) -- | Helper for 'AddRefence' that finds out the 'entityID'. addReference :: Show a => [EntityDef a] -> DBName -> DBName -> DBName -> AlterColumn addReference allDefs fkeyname reftable cname = AddReference reftable fkeyname [cname] [id_] where id_ = maybe (error $ "Could not find ID of entity " ++ show reftable ++ " (allDefs = " ++ show allDefs ++ ")") id $ do entDef <- find ((== reftable) . entityDB) allDefs return (entityID entDef) data AlterColumn = Change Column | Add' Column | Drop | Default String | NoDefault | Update' String | AddReference DBName DBName [DBName] [DBName] | DropReference DBName type AlterColumn' = (DBName, AlterColumn) data AlterTable = AddUniqueConstraint DBName [(DBName, FieldType)] | DropUniqueConstraint DBName data AlterDB = AddTable String | AlterColumn DBName AlterColumn' | AlterTable DBName AlterTable 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 :: MySQL.ConnectInfo -> (Text -> IO Statement) -> EntityDef a -> IO ( [Either Text (Either Column (DBName, [DBName]))] -- ID column , [Either Text (Either Column (DBName, [DBName]))] -- everything else ) getColumns connectInfo getter def = do -- Find out ID column. stmtIdClmn <- getter "SELECT COLUMN_NAME, \ \IS_NULLABLE, \ \DATA_TYPE, \ \COLUMN_DEFAULT \ \FROM INFORMATION_SCHEMA.COLUMNS \ \WHERE TABLE_SCHEMA = ? \ \AND TABLE_NAME = ? \ \AND COLUMN_NAME = ?" inter1 <- runResourceT $ stmtQuery stmtIdClmn vals $$ CL.consume ids <- runResourceT $ CL.sourceList inter1 $$ helperClmns -- avoid nested queries -- Find out all columns. stmtClmns <- getter "SELECT COLUMN_NAME, \ \IS_NULLABLE, \ \DATA_TYPE, \ \COLUMN_DEFAULT \ \FROM INFORMATION_SCHEMA.COLUMNS \ \WHERE TABLE_SCHEMA = ? \ \AND TABLE_NAME = ? \ \AND COLUMN_NAME <> ?" inter2 <- runResourceT $ stmtQuery stmtClmns vals $$ CL.consume cs <- runResourceT $ CL.sourceList inter2 $$ helperClmns -- avoid nested queries -- Find out the constraints. stmtCntrs <- getter "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 <- runResourceT $ stmtQuery stmtCntrs vals $$ helperCntrs -- Return both return (ids, cs ++ us) where vals = [ PersistText $ pack $ MySQL.connectDatabase connectInfo , PersistText $ unDBName $ entityDB def , PersistText $ unDBName $ entityID def ] helperClmns = CL.mapM getIt =$ CL.consume where getIt = fmap (either Left (Right . Left)) . liftIO . getColumn connectInfo getter (entityDB def) helperCntrs = do let check [ PersistByteString cntrName , PersistByteString clmnName] = return ( T.decodeUtf8 cntrName , T.decodeUtf8 clmnName ) check other = fail $ "helperCntrs: unexpected " ++ show other rows <- mapM check =<< CL.consume return $ map (Right . Right . (DBName . fst . head &&& map (DBName . snd))) $ groupBy ((==) `on` fst) rows -- | Get the information about a column in a table. getColumn :: MySQL.ConnectInfo -> (Text -> IO Statement) -> DBName -> [PersistValue] -> IO (Either Text Column) getColumn connectInfo getter tname [ PersistByteString cname , PersistByteString null_ , PersistByteString type' , default'] = fmap (either (Left . pack) Right) $ runErrorT $ do -- Default value default_ <- case default' of PersistNull -> return Nothing PersistText t -> return (Just t) PersistByteString bs -> case T.decodeUtf8' bs of Left exc -> fail $ "Invalid default column: " ++ show default' ++ " (error: " ++ show exc ++ ")" Right t -> return (Just t) _ -> fail $ "Invalid default column: " ++ show default' -- Column type type_ <- parseType type' -- Foreign key (if any) stmt <- lift $ getter "SELECT REFERENCED_TABLE_NAME, \ \CONSTRAINT_NAME, \ \ORDINAL_POSITION \ \FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE \ \WHERE TABLE_SCHEMA = ? \ \AND TABLE_NAME = ? \ \AND COLUMN_NAME = ? \ \AND REFERENCED_TABLE_SCHEMA = ? \ \ORDER BY CONSTRAINT_NAME, \ \COLUMN_NAME" let vars = [ PersistText $ pack $ MySQL.connectDatabase connectInfo , PersistText $ unDBName $ tname , PersistByteString cname , PersistText $ pack $ MySQL.connectDatabase connectInfo ] cntrs <- runResourceT $ stmtQuery stmt vars $$ CL.consume ref <- case cntrs of [] -> return Nothing [[PersistByteString tab, PersistByteString ref, PersistInt64 pos]] -> return $ if pos == 1 then Just (DBName $ T.decodeUtf8 tab, DBName $ T.decodeUtf8 ref) else Nothing _ -> fail "MySQL.getColumn/getRef: never here" -- Okay! return Column { cName = DBName $ T.decodeUtf8 cname , cNull = null_ == "YES" , cSqlType = type_ , cDefault = default_ , cDefaultConstraintName = Nothing , cMaxLen = Nothing -- FIXME: maxLen , cReference = ref } getColumn _ _ _ x = return $ Left $ pack $ "Invalid result from INFORMATION_SCHEMA: " ++ show x -- | Parse the type of column as returned by MySQL's -- @INFORMATION_SCHEMA@ tables. parseType :: Monad m => ByteString -> m SqlType parseType "tinyint" = return SqlBool -- Ints parseType "int" = return SqlInt32 parseType "short" = return SqlInt32 parseType "long" = return SqlInt64 parseType "longlong" = return SqlInt64 parseType "mediumint" = return SqlInt32 parseType "bigint" = return SqlInt64 -- Double parseType "float" = return SqlReal parseType "double" = return SqlReal parseType "decimal" = return SqlReal parseType "newdecimal" = return SqlReal -- Text parseType "varchar" = return SqlString parseType "varstring" = return SqlString parseType "string" = return SqlString parseType "text" = return SqlString parseType "tinytext" = return SqlString parseType "mediumtext" = return SqlString parseType "longtext" = return SqlString -- ByteString parseType "varbinary" = return SqlBlob parseType "blob" = return SqlBlob parseType "tinyblob" = return SqlBlob parseType "mediumblob" = return SqlBlob parseType "longblob" = return SqlBlob -- Time-related parseType "time" = return SqlTime parseType "datetime" = return SqlDayTime parseType "timestamp" = return SqlDayTime parseType "date" = return SqlDay parseType "newdate" = return SqlDay parseType "year" = return SqlDay -- Other parseType b = return $ SqlOther $ T.decodeUtf8 b ---------------------------------------------------------------------- -- | @getAlters allDefs tblName new old@ finds out what needs to -- be changed from @old@ to become @new@. getAlters :: Show a => [EntityDef a] -> DBName -> ([Column], [(DBName, [DBName])]) -> ([Column], [(DBName, [DBName])]) -> ([AlterColumn'], [AlterTable]) getAlters allDefs tblName (c1, u1) (c2, u2) = (getAltersC c1 c2, getAltersU u1 u2) where getAltersC [] old = concatMap dropColumn old getAltersC (new:news) old = let (alters, old') = findAlters tblName allDefs new old in alters ++ getAltersC news old' dropColumn col = map ((,) (cName col)) $ [DropReference n | Just (_, n) <- [cReference col]] ++ [Drop] getAltersU [] old = map (DropUniqueConstraint . fst) old getAltersU ((name, cols):news) old = case lookup name old of Nothing -> AddUniqueConstraint name (map findType 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 findType cols) : getAltersU news old' where findType = findTypeOfColumn allDefs tblName -- | @findAlters newColumn oldColumns@ finds out what needs to be -- changed in the columns @oldColumns@ for @newColumn@ to be -- supported. findAlters :: Show a => DBName -> [EntityDef a] -> Column -> [Column] -> ([AlterColumn'], [Column]) findAlters tblName allDefs col@(Column name isNull type_ def defConstraintName _maxLen ref) cols = case filter ((name ==) . cName) cols of -- new fkey that didnt exist before [] -> case ref of Nothing -> ([],[]) Just (tname, b) -> let cnstr = [addReference allDefs (refName tblName name) tname name] in (map ((,) tname) (Add' col : cnstr), cols) Column _ isNull' type_' def' defConstraintName' _maxLen' ref':_ -> let -- Foreign key refDrop = case (ref == ref', ref') of (False, Just (_, cname)) -> [(name, DropReference cname)] _ -> [] refAdd = case (ref == ref', ref) of (False, Just (tname, cname)) -> [(tname, addReference allDefs (refName tblName name) tname name)] _ -> [] -- Type and nullability modType | type_ == type_' && isNull == isNull' = [] | otherwise = [(name, Change col)] -- Default value modDef | def == def' = [] | otherwise = case def of Nothing -> [(name, NoDefault)] Just s -> [(name, Default $ T.unpack s)] in ( refDrop ++ modType ++ modDef ++ refAdd , filter ((name /=) . cName) cols ) ---------------------------------------------------------------------- -- | Prints the part of a @CREATE TABLE@ statement about a given -- column. showColumn :: Column -> String showColumn (Column n nu t def defConstraintName maxLen ref) = concat [ escapeDBName n , " " , showSqlType t maxLen , " " , if nu then "NULL" else "NOT NULL" , case def of Nothing -> "" Just s -> " DEFAULT " ++ T.unpack s , case ref of Nothing -> "" Just (s, _) -> " REFERENCES " ++ escapeDBName s ] -- | Renders an 'SqlType' in MySQL's format. showSqlType :: SqlType -> Maybe Integer -- ^ @maxlen@ -> String showSqlType SqlBlob Nothing = "BLOB" showSqlType SqlBlob (Just i) = "VARBINARY(" ++ show i ++ ")" showSqlType SqlBool _ = "TINYINT(1)" showSqlType SqlDay _ = "DATE" showSqlType SqlDayTime _ = "DATETIME" showSqlType SqlDayTimeZoned _ = "VARCHAR(50) CHARACTER SET utf8" showSqlType SqlInt32 _ = "INT" showSqlType SqlInt64 _ = "BIGINT" showSqlType SqlReal _ = "DOUBLE PRECISION" showSqlType (SqlNumeric s prec) _ = "NUMERIC(" ++ show s ++ "," ++ show prec ++ ")" showSqlType SqlString Nothing = "TEXT CHARACTER SET utf8" showSqlType SqlString (Just i) = "VARCHAR(" ++ show i ++ ") CHARACTER SET utf8" 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" )) = escapeDBName name ++ "(200)" escapeDBName' (name, (FTTypeCon _ "String" )) = escapeDBName name ++ "(200)" escapeDBName' (name, (FTTypeCon _ "ByteString")) = escapeDBName name ++ "(200)" 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 defConstraintName maxLen _ref)) = concat [ "ALTER TABLE " , escapeDBName table , " CHANGE " , escapeDBName oldName , " " , showColumn (Column n nu t def 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 (n, Update' s) = concat [ "UPDATE " , escapeDBName table , " SET " , escapeDBName n , "=" , s , " WHERE " , escapeDBName n , " IS NULL" ] showAlter table (_, AddReference reftable fkeyname t2 id2) = concat [ "ALTER TABLE " , escapeDBName table , " ADD CONSTRAINT " , escapeDBName fkeyname , " FOREIGN KEY(" , intercalate "," $ map escapeDBName t2 , ") REFERENCES " , escapeDBName reftable , "(" , intercalate "," $ map escapeDBName id2 , ")" ] showAlter table (_, DropReference cname) = concat [ "ALTER TABLE " , escapeDBName table , " DROP FOREIGN KEY " , escapeDBName cname ] refName :: DBName -> DBName -> DBName refName (DBName table) (DBName column) = DBName $ T.concat [table, "_", column, "_fkey"] ---------------------------------------------------------------------- -- | 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. } instance PersistConfig MySQLConf where type PersistConfigBackend MySQLConf = SqlPersistT type PersistConfigPool MySQLConf = ConnectionPool createPoolConfig (MySQLConf cs size) = createMySQLPool cs size runPool _ = runSqlPool loadConfig (Object o) = do database <- o .: "database" host <- o .: "host" port <- o .: "port" user <- o .: "user" password <- o .: "password" pool <- o .: "poolsize" let ci = MySQL.defaultConnectInfo { MySQL.connectHost = host , MySQL.connectPort = port , MySQL.connectUser = user , MySQL.connectPassword = password , MySQL.connectDatabase = database } return $ MySQLConf ci pool loadConfig _ = mzero 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.connectUser = user , MySQL.connectPassword = password , MySQL.connectDatabase = database } -> (myConnInfo conf) { MySQL.connectHost = maybeEnv host "HOST" , MySQL.connectPort = read $ maybeEnv (show port) "PORT" , MySQL.connectUser = maybeEnv user "USER" , MySQL.connectPassword = maybeEnv password "PASSWORD" , MySQL.connectDatabase = maybeEnv database "DATABASE" } }