{-# LANGUAGE ConstraintKinds #-}
{-# 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(..)
, mockMigration
) where
import Control.Arrow
import Control.Monad.Logger (MonadLogger, runNoLoggingT)
import Control.Monad.IO.Class (MonadIO (..))
import Control.Monad.Trans.Class (lift)
import Control.Monad.Trans.Error (ErrorT(..))
import Control.Monad.Trans.Reader (runReaderT)
import Control.Monad.Trans.Writer (runWriterT)
import Data.Monoid ((<>))
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.IORef
import Data.List (find, intercalate, sort, groupBy)
import Data.Pool (Pool)
import Data.Text (Text, pack)
import qualified Data.Text.IO as T
import Text.Read (readMaybe)
import System.Environment (getEnvironment)
import Data.Acquire (Acquire, mkAcquire, with)
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 Database.Persist.Sql.Types.Internal (mkPersistBackend)
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
import Control.Monad.Trans.Control (MonadBaseControl)
import Control.Monad.Trans.Resource (runResourceT)
-- | 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, MonadLogger m, MonadBaseControl IO m, IsSqlBackend backend)
=> MySQL.ConnectInfo
-- ^ Connection information.
-> Int
-- ^ Number of connections to be kept open in the pool.
-> (Pool backend -> 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 :: (MonadBaseControl IO m, MonadIO m, MonadLogger m, IsSqlBackend backend)
=> MySQL.ConnectInfo
-- ^ Connection information.
-> Int
-- ^ Number of connections to be kept open in the pool.
-> m (Pool backend)
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, MonadLogger m, IsSqlBackend backend)
=> MySQL.ConnectInfo
-- ^ Connection information.
-> (backend -> 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' :: (IsSqlBackend backend) => MySQL.ConnectInfo -> LogFunc -> IO backend
open' ci logFunc = do
conn <- MySQL.connect ci
MySQLBase.autocommit conn False -- disable autocommit!
smap <- newIORef $ Map.empty
return . mkPersistBackend $ SqlBackend
{ connPrepare = prepare' conn
, connStmtMap = smap
, connInsertSql = insertSql'
, connInsertManySql = Nothing
, connUpsertSql = Nothing
, 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
-- <http://dev.mysql.com/doc/refman/5.5/en/select.html>
, connRDBMS = "mysql"
, connLimitOffset = decorateSQLWithLimitOffset "LIMIT 18446744073709551615"
, connLogFunc = logFunc
}
-- | 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 =
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' :: MonadIO m
=> MySQL.Connection
-> MySQL.Query
-> [PersistValue]
-> Acquire (Source m [PersistValue])
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 `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 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.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 -> PersistDbSpecific 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
(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 uniques = flip concatMap udspair $ \(uname, ucols) ->
[ AlterTable name $
AddUniqueConstraint uname $
map (findTypeAndMaxLen 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 newcols val): 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
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 cols then [] else ","
, intercalate "," $ map showColumn cols
, ")"
]
where
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 = do
maxLenAttr <- find ((T.isPrefixOf "maxlen=") . T.toLower) (fieldAttrs fieldDef)
readMaybe . T.unpack . T.drop 7 $ maxLenAttr
-- | Helper for 'AddReference' that finds out the which primary key columns to reference.
addReference :: [EntityDef] -> DBName -> DBName -> DBName -> AlterColumn
addReference allDefs fkeyname reftable cname = AddReference reftable fkeyname [cname] referencedColumns
where
referencedColumns = maybe (error $ "Could not find ID of entity " ++ show reftable
++ " (allDefs = " ++ show allDefs ++ ")")
id $ do
entDef <- find ((== reftable) . entityDB) allDefs
return $ map fieldDB $ entityKeyFields entDef
data AlterColumn = Change Column
| Add' Column
| Drop
| Default String
| NoDefault
| 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
| DropReference DBName
type AlterColumn' = (DBName, AlterColumn)
data AlterTable = AddUniqueConstraint DBName [(DBName, FieldType, Integer)]
| 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
-> 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 <- with (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, \
\COLUMN_TYPE, \
\COLUMN_DEFAULT \
\FROM INFORMATION_SCHEMA.COLUMNS \
\WHERE TABLE_SCHEMA = ? \
\AND TABLE_NAME = ? \
\AND COLUMN_NAME <> ?"
inter2 <- with (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 <- with (stmtQuery stmtCntrs vals) ($$ helperCntrs)
-- Return both
return (ids, cs ++ us)
where
vals = [ PersistText $ pack $ MySQL.connectDatabase connectInfo
, PersistText $ unDBName $ entityDB def
, PersistText $ unDBName $ fieldDB $ entityId def ]
helperClmns = CL.mapM getIt =$ CL.consume
where
getIt = fmap (either Left (Right . Left)) .
liftIO .
getColumn connectInfo getter (entityDB def)
helperCntrs = do
let check [ PersistText cntrName
, PersistText clmnName] = return ( cntrName, clmnName )
check other = fail $ "helperCntrs: unexpected " ++ show other
rows <- mapM check =<< CL.consume
return $ map (Right . Right . (DBName . fst . head &&& map (DBName . snd)))
$ groupBy ((==) `on` fst) rows
-- | Get the information about a column in a table.
getColumn :: MySQL.ConnectInfo
-> (Text -> IO Statement)
-> DBName
-> [PersistValue]
-> IO (Either Text Column)
getColumn connectInfo getter tname [ PersistText cname
, PersistText null_
, PersistText type'
, default'] =
fmap (either (Left . pack) Right) $
runErrorT $ do
-- Default value
default_ <- case default' of
PersistNull -> return Nothing
PersistText t -> return (Just t)
PersistByteString bs ->
case T.decodeUtf8' bs of
Left exc -> fail $ "Invalid default column: " ++
show default' ++ " (error: " ++
show exc ++ ")"
Right t -> return (Just t)
_ -> fail $ "Invalid default column: " ++ show default'
-- Foreign key (if any)
stmt <- lift $ getter "SELECT REFERENCED_TABLE_NAME, \
\CONSTRAINT_NAME, \
\ORDINAL_POSITION \
\FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE \
\WHERE TABLE_SCHEMA = ? \
\AND TABLE_NAME = ? \
\AND COLUMN_NAME = ? \
\AND REFERENCED_TABLE_SCHEMA = ? \
\ORDER BY CONSTRAINT_NAME, \
\COLUMN_NAME"
let vars = [ PersistText $ pack $ MySQL.connectDatabase connectInfo
, PersistText $ unDBName $ tname
, PersistText cname
, PersistText $ pack $ MySQL.connectDatabase connectInfo ]
cntrs <- with (stmtQuery stmt vars) ($$ CL.consume)
ref <- case cntrs of
[] -> return Nothing
[[PersistText tab, PersistText ref, PersistInt64 pos]] ->
return $ if pos == 1 then Just (DBName tab, DBName ref) else Nothing
_ -> fail "MySQL.getColumn/getRef: never here"
-- Okay!
return Column
{ cName = DBName $ cname
, cNull = null_ == "YES"
, cSqlType = parseType 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 :: Text -> SqlType
parseType "bigint(20)" = SqlInt64
parseType "decimal(32,20)" = SqlNumeric 32 20
{-
parseType "tinyint" = SqlBool
-- Ints
parseType "int" = SqlInt32
--parseType "short" = SqlInt32
--parseType "long" = SqlInt64
--parseType "longlong" = SqlInt64
--parseType "mediumint" = SqlInt32
parseType "bigint" = SqlInt64
-- Double
--parseType "float" = SqlReal
parseType "double" = SqlReal
--parseType "decimal" = SqlReal
--parseType "newdecimal" = SqlReal
-- Text
parseType "varchar" = SqlString
--parseType "varstring" = SqlString
--parseType "string" = SqlString
parseType "text" = SqlString
--parseType "tinytext" = SqlString
--parseType "mediumtext" = SqlString
--parseType "longtext" = SqlString
-- ByteString
parseType "varbinary" = SqlBlob
parseType "blob" = SqlBlob
--parseType "tinyblob" = SqlBlob
--parseType "mediumblob" = SqlBlob
--parseType "longblob" = SqlBlob
-- Time-related
parseType "time" = SqlTime
parseType "datetime" = SqlDayTime
--parseType "timestamp" = SqlDayTime
parseType "date" = SqlDay
--parseType "newdate" = SqlDay
--parseType "year" = SqlDay
-}
parseType b = SqlOther b
----------------------------------------------------------------------
-- | @getAlters allDefs tblName new old@ finds out what needs to
-- be changed from @old@ to become @new@.
getAlters :: [EntityDef]
-> 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 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 newColumn oldColumns@ finds out what needs to be
-- changed in the columns @oldColumns@ for @newColumn@ to be
-- supported.
findAlters :: DBName -> [EntityDef] -> 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 -> ([(name, Add' col)],[])
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 | showSqlType type_ maxLen False `ciEquals` showSqlType type_' maxLen' False && 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 )
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 _defConstraintName maxLen ref) = concat
[ escapeDBName n
, " "
, showSqlType t maxLen True
, " "
, 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@
-> 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 utf8"
showSqlType SqlString Nothing False = "TEXT"
showSqlType SqlString (Just i) True = "VARCHAR(" ++ show i ++ ") CHARACTER SET utf8"
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 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.
} 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) = mkColumns allDefs val
let udspair = map udToPair udefs
case ([], [], partitionEithers []) 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 (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 newcols val): 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
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}
result = runReaderT . runWriterT . runWriterT $ mig
resp <- result sqlbackend
mapM_ T.putStrLn $ map snd $ snd resp