5ce5d2e · typeable/postgresql-simple

git.iko.soy/typeable/postgresql-simple

Copy: Show error message on failure

This ensures that the exception thrown includes the cause. Sadly it seems that the only way to determine that a COPY IN has failed is to fail to parse the row count. It seems that all of the getResults calls after the putCopyEnd command inexplicably return success, despite the fact that something failed.

commit5ce5d2ecbc397e6c38b75520d37ff5b5bd0b3ea1 authorBen Gamari <ben@smart-cactus.org> dateThu 19 May 2016, 16:01 (10 years ago) parent1e366a2

1 file changed+3−1

compare with master

unifiedsplit

src/Database/PostgreSQL/Simple/Copy.hs+3−1

src/Database/PostgreSQL/Simple/Copy.hs+3−1

@@ -224,7 +224,9 @@ getCopyCommandTag funcName pqconn = do

224224 consumeResults pqconn

225225 let rowCount = P.string "COPY " *> (P.decimal <* P.endOfInput)

226226 case P.parseOnly rowCount cmdStat of

227− Left _ -> fail errCmdStatusFmt

227+ Left _ -> do mmsg <- PQ.errorMessage pqconn

228+ fail $ errCmdStatusFmt

229+ ++ maybe "" (\msg -> "\nConnection error: "++B.unpack msg) mmsg

228230 Right n -> return $! n

229231 where

230232 errCmdStatus = B.unpack funcName ++ ": failed to fetch command status"