HDBC with SQL Server / OBDC
am trying to do a simple DB connection from Haskell to a SQL Server 2005 (on Windows obviously). The DSN name ("Nylon") works from C++ but when running the below example (or any other I can think of) ghci crashes. Does anyone know a resolution for this or where the problem can possible be ? GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help Loading package base ... linking ... done. Prelude> :m Database.HDBC Prelude Database.HDBC> :m + Database.HDBC.ODBC Prelude Database.HDBC Database.HDBC.ODBC> do { conn <- connectODBC "DSN=Nylon"; xs <- getTables conn; putStr $ head xs; } Loading package array-0.1.0.0 ... linking ... done. Loading package containers-0.1.0.1 ... linking ... done. Loading package bytestring-0.9.0.1 ... linking ... done. Loading package old-locale-1.0.0.0 ... linking ... done. Loading package old-time-1.0.0.0 ... linking ... done. Loading package mtl-1.1.0.0 ... linking ... done. Loading package HDBC-1.1.4 ... linking ... done. Loading package HDBC-odbc-1.1.4.3 ... linking ... done. CRASH !!! Thanks Morten
Hi Morten, On 26/05/2008 2:24 AM, you wrote:
am trying to do a simple DB connection from Haskell to a SQL Server 2005 (on Windows obviously). The DSN name ("Nylon") works from C++ but when running the below example (or any other I can think of) ghci crashes. Does anyone know a resolution for this or where the problem can possible be ?
I had the same problem last week. I found that GHCi would silently crash, but GHC would give link errors on the foreign imported functions from the odbc32 library. Changing the calling convention from 'ccall' to 'stdcall' for the 16 'sql.h' imports fixed the problem for me, but I'm not convinced that's the 'right way' to fix it (ccall is surely the appropriate calling convention for using ODBC on Unix, for example).
GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help Loading package base ... linking ... done. Prelude> :m Database.HDBC Prelude Database.HDBC> :m + Database.HDBC.ODBC Prelude Database.HDBC Database.HDBC.ODBC> do { conn <- connectODBC "DSN=Nylon"; xs <- getTables conn; putStr $ head xs; } Loading package array-0.1.0.0 ... linking ... done. Loading package containers-0.1.0.1 ... linking ... done. Loading package bytestring-0.9.0.1 ... linking ... done. Loading package old-locale-1.0.0.0 ... linking ... done. Loading package old-time-1.0.0.0 ... linking ... done. Loading package mtl-1.1.0.0 ... linking ... done. Loading package HDBC-1.1.4 ... linking ... done. Loading package HDBC-odbc-1.1.4.3 ... linking ... done. CRASH !!!
Regards, Andrew
On Sun, May 25, 2008 at 8:04 PM, Andrew Appleyard < andrew.appleyard@gmail.com> wrote:
I had the same problem last week. I found that GHCi would silently crash, but GHC would give link errors on the foreign imported functions from the odbc32 library. Changing the calling convention from 'ccall' to 'stdcall' for the 16 'sql.h' imports fixed the problem for me, but I'm not convinced that's the 'right way' to fix it (ccall is surely the appropriate calling convention for using ODBC on Unix, for example).
If the calling convention is stdcall on Windows and ccall on other OS then it should be defined based on the OS. This can be done by updating the .hsc files to define the calling convention as a "macro" depending on the OS type. #ifdef mingw32_HOST_OS #let CALLCONV = "stdcall" #else #let CALLCONV = "ccall" #endif And the foreign import should use CALLCONV instead of ccall. This should make it work on Windows and not break it on Linux. Olivier.
On Wed, May 28, 2008 at 12:46 AM, Olivier Boudry
If the calling convention is stdcall on Windows and ccall on other OS then it should be defined based on the OS. This can be done by updating the .hsc files to define the calling convention as a "macro" depending on the OS type.
#ifdef mingw32_HOST_OS #let CALLCONV = "stdcall" #else #let CALLCONV = "ccall" #endif
And the foreign import should use CALLCONV instead of ccall.
This should make it work on Windows and not break it on Linux.
Thanks Olivier, that's neater than I thought. I'll put a patch together. -- Andrew
On Sun, 25 May 2008, Morten Holm Pedersen wrote:
am trying to do a simple DB connection from Haskell to a SQL Server 2005 (on Windows obviously). The DSN name ("Nylon") works from C++ but when running the below example (or any other I can think of) ghci crashes.
I have been having the same (or similar) problem with HDBC and SQL Server. I have no problem using HDBC and SQLite on Windows, and also have no problems with perl's DBI and DBD::ODBC connecting to the SQL Server database with the same DSN. But I don't know where to point the finger, and I don't know what to do next. It does seem strange that there is no error message when ghci crashes. -- Dr Bean Autonomous language learning: My next project after overseeing the making of laborers into athletes.
On Sunday 25 May 2008 11:24:20 am Morten Holm Pedersen wrote:
am trying to do a simple DB connection from Haskell to a SQL Server 2005 (on Windows obviously). The DSN name ("Nylon") works from C++ but when running the below example (or any other I can think of) ghci crashes. Does anyone know a resolution for this or where the problem can possible be ?
First off, I'd suggest separating out the steps in your do block to individual pieces so you can isolate where the crash is. Also, what sort of error message do you get when the crash occurs? And are you using a MingW GHC? -- John
John Goerzen wrote:
On Sunday 25 May 2008 11:24:20 am Morten Holm Pedersen wrote:
am trying to do a simple DB connection from Haskell to a SQL Server 2005 (on Windows obviously). The DSN name ("Nylon") works from C++ but when running the below example (or any other I can think of) ghci crashes. Does anyone know a resolution for this or where the problem can possible be ?
First off, I'd suggest separating out the steps in your do block to individual pieces so you can isolate where the crash is. Also, what sort of error message do you get when the crash occurs? And are you using a MingW GHC?
-- John
I am running it in plain Windows (from cmd). The text in the mail is the full communication from the system - ie. just stops without any message. Sometimes Windows gives an errors a well. The do was just an attemp to illustrate. Really I just need to do con=connectODBC "DSN=Nylon" and then write "con" on the GHCi prompt to crash the system. Morten
participants (6)
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Andrew Appleyard -
Greg Matheson -
John Goerzen -
Morten Holm Pedersen -
Morten Holm Pedersen -
Olivier Boudry