1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE OverloadedStrings #-}
module Database.Persist.Sql.Raw where
import Database.Persist
import Database.Persist.Sql.Types
import Database.Persist.Sql.Class
import qualified Data.Map as Map
import Control.Monad.IO.Class (liftIO)
import Data.IORef (writeIORef, readIORef, newIORef)
import Control.Exception (throwIO)
import Control.Monad (when, liftM)
import Data.Text (Text, pack)
import Control.Monad.Logger (logDebugS)
import Data.Int (Int64)
import Control.Monad.Trans.Class (lift)
import qualified Data.Text as T
import Data.Conduit
import Control.Monad.Trans.Resource (MonadResource)
rawQuery :: (MonadSqlPersist m, MonadResource m)
=> Text
-> [PersistValue]
-> Source m [PersistValue]
rawQuery sql vals = do
lift $ $logDebugS (pack "SQL") $ pack $ show sql ++ " " ++ show vals
conn <- lift askSqlConn
bracketP
(getStmtConn conn sql)
stmtReset
(flip stmtQuery vals)
rawExecute :: MonadSqlPersist m => Text -> [PersistValue] -> m ()
rawExecute x y = liftM (const ()) $ rawExecuteCount x y
rawExecuteCount :: MonadSqlPersist m => Text -> [PersistValue] -> m Int64
rawExecuteCount sql vals = do
$logDebugS (pack "SQL") $ pack $ show sql ++ " " ++ show vals
stmt <- getStmt sql
res <- liftIO $ stmtExecute stmt vals
liftIO $ stmtReset stmt
return res
getStmt :: MonadSqlPersist m => Text -> m Statement
getStmt sql = do
conn <- askSqlConn
liftIO $ getStmtConn conn sql
getStmtConn :: Connection -> Text -> IO Statement
getStmtConn conn sql = do
smap <- liftIO $ readIORef $ connStmtMap conn
case Map.lookup sql smap of
Just stmt -> return stmt
Nothing -> do
stmt' <- liftIO $ connPrepare conn sql
iactive <- liftIO $ newIORef True
let stmt = Statement
{ stmtFinalize = do
active <- readIORef iactive
if active
then do
stmtFinalize stmt'
writeIORef iactive False
else return ()
, stmtReset = do
active <- readIORef iactive
when active $ stmtReset stmt'
, stmtExecute = \x -> do
active <- readIORef iactive
if active
then stmtExecute stmt' x
else throwIO $ StatementAlreadyFinalized sql
, stmtQuery = \x -> do
active <- liftIO $ readIORef iactive
if active
then stmtQuery stmt' x
else liftIO $ throwIO $ StatementAlreadyFinalized sql
}
liftIO $ writeIORef (connStmtMap conn) $ Map.insert sql stmt smap
return stmt
-- | Execute a raw SQL statement and return its results as a
-- list.
--
-- If you're using 'Entity'@s@ (which is quite likely), then you
-- /must/ use entity selection placeholders (double question
-- mark, @??@). These @??@ placeholders are then replaced for
-- the names of the columns that we need for your entities.
-- You'll receive an error if you don't use the placeholders.
-- Please see the 'Entity'@s@ documentation for more details.
--
-- You may put value placeholders (question marks, @?@) in your
-- SQL query. These placeholders are then replaced by the values
-- you pass on the second parameter, already correctly escaped.
-- You may want to use 'toPersistValue' to help you constructing
-- the placeholder values.
--
-- Since you're giving a raw SQL statement, you don't get any
-- guarantees regarding safety. If 'rawSql' is not able to parse
-- the results of your query back, then an exception is raised.
-- However, most common problems are mitigated by using the
-- entity selection placeholder @??@, and you shouldn't see any
-- error at all if you're not using 'Single'.
rawSql :: (RawSql a, MonadSqlPersist m, MonadResource m)
=> Text -- ^ SQL statement, possibly with placeholders.
-> [PersistValue] -- ^ Values to fill the placeholders.
-> m [a]
rawSql stmt = run
where
getType :: (x -> m [a]) -> a
getType = error "rawSql.getType"
x = getType run
process = rawSqlProcessRow
withStmt' colSubsts params = do
rawQuery sql params
where
sql = T.concat $ makeSubsts colSubsts $ T.splitOn placeholder stmt
placeholder = "??"
makeSubsts (s:ss) (t:ts) = t : s : makeSubsts ss ts
makeSubsts [] [] = []
makeSubsts [] ts = [T.intercalate placeholder ts]
makeSubsts ss [] = error (concat err)
where
err = [ "rawsql: there are still ", show (length ss)
, "'??' placeholder substitutions to be made "
, "but all '??' placeholders have already been "
, "consumed. Please read 'rawSql's documentation "
, "on how '??' placeholders work."
]
run params = do
conn <- askSqlConn
let (colCount, colSubsts) = rawSqlCols (connEscapeName conn) x
withStmt' colSubsts params $$ firstRow colCount
firstRow colCount = do
mrow <- await
case mrow of
Nothing -> return []
Just row
| colCount == length row -> getter mrow
| otherwise -> fail $ concat
[ "rawSql: wrong number of columns, got "
, show (length row), " but expected ", show colCount
, " (", rawSqlColCountReason x, ")." ]
getter = go id
where
go acc Nothing = return (acc [])
go acc (Just row) =
case process row of
Left err -> fail (T.unpack err)
Right r -> await >>= go (acc . (r:))
|
