Justin Bailey wrote:
I have run into a weird bug with HDBC-odbc that only occurs on my unix system. When I execute a select which returns more than 435 rows twice in the same process, the second execution fails with this error message:
OK, sorry for missing that detail. Are you *sure* it really is the same scenario? Here, you are connecting to the SQL database twice, but calling disconnect neither time. Did you check your MySQL logs for why this connection is being rejected? Note that the garbage collection will eventually release the connection, but it is not guaranteed that this will happen prior to the second run -- and you might be running into connection limits in MySQL. If you show me your .odbc.ini, I can try to duplicate the issue locally. But I'd first suggest that you put disconnect at the proper place. I've simplified your code a bit and added a disconnect. Try this version: import System.Environment import Database.HDBC import Database.HDBC.ODBC import System.IO (hPutStrLn, stderr) -- Execute with DNS name as only argument. E.g.: -- ./TestMain localdb main = do [dsn] <- getArgs testMatches dsn testMatches dsn testMatches dsn = do handleSqlError $ do conn <- connectODBC $ "dsn=" ++ dsn -- 435 rows works fine, but not 445. rows <- quickQuery' conn "select 1 from information_schema.columns limit 445" [] let evaledRows = filter (\[id] -> (fromSql id) /= (-1 :: Int)) rows putStrLn $ "Got " ++ show (length evaledRows) disconnect conn This compiles, but I haven't tried to run it. A few notes: 1) Your getAllRows essentially mimiced the built-in quickQuery' function. 2) I switched from using your handler to using handleSqlError so we can get a crash when the error comes in instead of just the message. 3) I added the disconnect at the end of testMatches so you aren't relying on the garbage collector to shut down the database connection. Let me know if that works for you. -- John