HDBC-odbc-2.2.3.1: Database/HDBC/ODBC/Connection.hsc
-- -*- mode: haskell; -*-
{-# CFILES hdbc-odbc-helper.c #-}
-- Above line for hugs
{-
Copyright (C) 2005-2009 John Goerzen <jgoerzen@complete.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-}
module Database.HDBC.ODBC.Connection (connectODBC, Impl.Connection) where
import Database.HDBC.Types
import Database.HDBC
import Database.HDBC.DriverUtils
import qualified Database.HDBC.ODBC.ConnectionImpl as Impl
import Database.HDBC.ODBC.Types
import Database.HDBC.ODBC.Statement
import Foreign.C.Types
import Foreign.C.String
import Foreign.Marshal
import Foreign.Storable
import Database.HDBC.ODBC.Utils
import Foreign.ForeignPtr
import Foreign.Ptr
import Data.Word
import Data.Int
import Control.Concurrent.MVar
import Control.Monad (when)
import qualified Data.ByteString as B
import qualified Data.ByteString.UTF8 as BUTF8
#ifdef mingw32_HOST_OS
#include <windows.h>
#endif
#include <sql.h>
#include <sqlext.h>
#ifdef mingw32_HOST_OS
#let CALLCONV = "stdcall"
#else
#let CALLCONV = "ccall"
#endif
{- | Connect to an ODBC server.
For information on the meaning of the passed string, please see:
<http://msdn2.microsoft.com/en-us/library/ms715433(VS.85).aspx>
An example string is:
>"DSN=hdbctest1"
This, and all other functions that use ODBC directly or indirectly, can raise
SqlErrors just like other HDBC backends. The seErrorMsg field is specified
as a String in HDBC. ODBC specifies this data as a list of strings.
Therefore, this driver uses show on the data from ODBC. For friendly display,
or handling of individual component messages in your code, you can use
read on the seErrorMsg field in a context that expects @[String]@.
Important note for MySQL users:
Unless you are going to use InnoDB tables, you are strongly encouraged to set
>Option = 262144
in your odbc.ini (for Unix users), or to disable transaction support in your
DSN setup for Windows users.
If you fail to do this, the MySQL ODBC driver will incorrectly state that it
supports transactions. dbTransactionSupport will incorrectly return True.
commit and rollback will then silently fail. This is certainly /NOT/ what you
want. It is a bug (or misfeature) in the MySQL driver, not in HDBC.
You should ignore this advice if you are using InnoDB tables.
-}
connectODBC :: String -> IO Impl.Connection
connectODBC args = B.useAsCStringLen (BUTF8.fromString args) $ \(cs, cslen) ->
alloca $ \(penvptr::Ptr (Ptr CEnv)) ->
alloca $ \(pdbcptr::Ptr (Ptr CConn)) ->
do -- Create the Environment Handle
rc1 <- sqlAllocHandle #{const SQL_HANDLE_ENV}
nullPtr -- {const SQL_NULL_HANDLE}
(castPtr penvptr)
envptr <- peek penvptr
checkError "connectODBC/alloc env" (EnvHandle envptr) rc1
sqlSetEnvAttr envptr #{const SQL_ATTR_ODBC_VERSION}
(getSqlOvOdbc3) 0
-- Create the DBC handle.
sqlAllocHandle #{const SQL_HANDLE_DBC} (castPtr envptr)
(castPtr pdbcptr)
>>= checkError "connectODBC/alloc dbc"
(EnvHandle envptr)
dbcptr <- peek pdbcptr
wrappeddbcptr <- wrapconn dbcptr envptr nullPtr
fdbcptr <- newForeignPtr sqlFreeHandleDbc_ptr wrappeddbcptr
-- Now connect.
sqlDriverConnect dbcptr nullPtr cs (fromIntegral cslen)
nullPtr 0 nullPtr
#{const SQL_DRIVER_NOPROMPT}
>>= checkError "connectODBC/sqlDriverConnect"
(DbcHandle dbcptr)
mkConn args fdbcptr
-- FIXME: environment vars may have changed, should use pgsql enquiries
-- for clone.
mkConn :: String -> Conn -> IO Impl.Connection
mkConn args iconn = withConn iconn $ \cconn ->
alloca $ \plen ->
alloca $ \psqlusmallint ->
allocaBytes 128 $ \pbuf ->
do
children <- newMVar []
sqlGetInfo cconn #{const SQL_DBMS_VER} (castPtr pbuf) 127 plen
>>= checkError "sqlGetInfo SQL_DBMS_VER" (DbcHandle cconn)
len <- peek plen
serverver <- peekCStringLen (pbuf, fromIntegral len)
sqlGetInfo cconn #{const SQL_DRIVER_VER} (castPtr pbuf) 127 plen
>>= checkError "sqlGetInfo SQL_DRIVER_VER" (DbcHandle cconn)
len <- peek plen
proxiedclientver <- peekCStringLen (pbuf, fromIntegral len)
sqlGetInfo cconn #{const SQL_ODBC_VER} (castPtr pbuf) 127 plen
>>= checkError "sqlGetInfo SQL_ODBC_VER" (DbcHandle cconn)
len <- peek plen
clientver <- peekCStringLen (pbuf, fromIntegral len)
sqlGetInfo cconn #{const SQL_DBMS_NAME} (castPtr pbuf) 127 plen
>>= checkError "sqlGetInfo SQL_DBMS_NAME" (DbcHandle cconn)
len <- peek plen
clientname <- peekCStringLen (pbuf, fromIntegral len)
sqlGetInfo cconn #{const SQL_TXN_CAPABLE} (castPtr psqlusmallint)
0 nullPtr
>>= checkError "sqlGetInfo SQL_TXN_CAPABLE" (DbcHandle cconn)
txninfo <- ((peek psqlusmallint)::IO (#{type SQLUSMALLINT}))
let txnsupport = txninfo /= #{const SQL_TC_NONE}
when txnsupport
(disableAutoCommit cconn
>>= checkError "sqlSetConnectAttr" (DbcHandle cconn)
)
return $ Impl.Connection {
Impl.getQueryInfo = fGetQueryInfo iconn children,
Impl.disconnect = fdisconnect iconn children,
Impl.commit = fcommit iconn,
Impl.rollback = frollback iconn,
Impl.run = frun iconn children,
Impl.prepare = newSth iconn children,
Impl.clone = connectODBC args,
-- FIXME: add clone
Impl.hdbcDriverName = "odbc",
Impl.hdbcClientVer = clientver,
Impl.proxiedClientName = clientname,
Impl.proxiedClientVer = proxiedclientver,
Impl.dbServerVer = serverver,
Impl.dbTransactionSupport = txnsupport,
Impl.getTables = fgettables iconn,
Impl.describeTable = fdescribetable iconn
}
--------------------------------------------------
-- Guts here
--------------------------------------------------
frun conn children query args =
do sth <- newSth conn children query
res <- execute sth args
finish sth
return res
fcommit iconn = withConn iconn $ \cconn ->
sqlEndTran #{const SQL_HANDLE_DBC} cconn #{const SQL_COMMIT}
>>= checkError "sqlEndTran commit" (DbcHandle cconn)
frollback iconn = withConn iconn $ \cconn ->
sqlEndTran #{const SQL_HANDLE_DBC} cconn #{const SQL_ROLLBACK}
>>= checkError "sqlEndTran rollback" (DbcHandle cconn)
fdisconnect iconn mchildren = withRawConn iconn $ \rawconn ->
withConn iconn $ \llconn ->
do closeAllChildren mchildren
res <- sqlFreeHandleDbc_app rawconn
-- FIXME: will this checkError segfault?
checkError "disconnect" (DbcHandle $ llconn) res
foreign import #{CALLCONV} unsafe "sql.h SQLAllocHandle"
sqlAllocHandle :: #{type SQLSMALLINT} -> Ptr () ->
Ptr () -> IO (#{type SQLRETURN})
foreign import ccall unsafe "hdbc-odbc-helper.h wrapobjodbc_extra"
wrapconn :: Ptr CConn -> Ptr CEnv -> Ptr WrappedCConn -> IO (Ptr WrappedCConn)
foreign import ccall unsafe "hdbc-odbc-helper.h &sqlFreeHandleDbc_finalizer"
sqlFreeHandleDbc_ptr :: FunPtr (Ptr WrappedCConn -> IO ())
foreign import ccall unsafe "hdbc-odbc-helper.h sqlFreeHandleDbc_app"
sqlFreeHandleDbc_app :: Ptr WrappedCConn -> IO (#{type SQLRETURN})
foreign import #{CALLCONV} unsafe "sql.h SQLSetEnvAttr"
sqlSetEnvAttr :: Ptr CEnv -> #{type SQLINTEGER} ->
Ptr () -> #{type SQLINTEGER} -> IO #{type SQLRETURN}
foreign import #{CALLCONV} unsafe "sql.h SQLDriverConnect"
sqlDriverConnect :: Ptr CConn -> Ptr () -> CString -> #{type SQLSMALLINT}
-> CString -> #{type SQLSMALLINT}
-> Ptr #{type SQLSMALLINT} -> #{type SQLUSMALLINT}
-> IO #{type SQLRETURN}
foreign import ccall unsafe "hdbc-odbc-helper.h getSqlOvOdbc3"
getSqlOvOdbc3 :: Ptr ()
foreign import ccall unsafe "hdbc-odbc-helper.h SQLSetConnectAttr"
sqlSetConnectAttr :: Ptr CConn -> #{type SQLINTEGER}
-> Ptr #{type SQLUINTEGER} -> #{type SQLINTEGER}
-> IO #{type SQLRETURN}
foreign import #{CALLCONV} unsafe "sql.h SQLEndTran"
sqlEndTran :: #{type SQLSMALLINT} -> Ptr CConn -> #{type SQLSMALLINT}
-> IO #{type SQLRETURN}
foreign import ccall unsafe "hdbc-odbc-helper.h disableAutoCommit"
disableAutoCommit :: Ptr CConn -> IO #{type SQLRETURN}
foreign import #{CALLCONV} unsafe "sql.h SQLGetInfo"
sqlGetInfo :: Ptr CConn -> #{type SQLUSMALLINT} -> Ptr () ->
#{type SQLSMALLINT} -> Ptr #{type SQLSMALLINT} ->
IO #{type SQLRETURN}