Thanks for the response. It's always nice to get detailed feedback on something. I've added checks for the things you mentioned: On Thu, 2006-01-05 at 19:38 -0800, Herve Pages wrote: > > res = dbSendQuery(con, "INSERT INTO mytable VALUES ('bla', 'bla')") > Then with the patched PgSQLgetResult() function, you get: > > dbGetResult(res) > Error in dbGetResult.PgSQL.result(res) : > > No error message at all! > I agree this is the consequence of the user misusing the dbGetResult() > function. > But it would be nice if we could keep the "Query did not produce any tuples" > message for this special case. We're in luck; there are two separate PQresultStatus return values to distinguish those cases, one for successful no-tuple-producing commands (like your insert example), and one for successful tuple-producing commands (queries). I've added a new check in the diff below. > Also, the PgSQLcolumnInfo() C function > (internal for dbColumnInfo() R function) starts with: > if (PQresultStatus(result) != PGRES_TUPLES_OK) > > Wouldn't it make sense to make the same change here too? > Just wondering... I'm not really familiar with the RdbiPgSQL > package though. I agree, this makes sense. The other case is the combination of the two things you mentioned (trying to do a dbColumnInfo on the result of something like an INSERT). With the extra checks: > res <- dbSendQuery(conn, "INSERT INTO mytable VALUES ('bla', 'bla')") > dbGetResult(res) Error in dbGetResult.PgSQL.result(res) : Query did not produce any tuples > dbColumnInfo(res) Error in dbColumnInfo.PgSQL.result(res) : Query did not produce any tuples > res <- dbSendQuery(conn, "SELECT FROM mytable") > dbGetResult(res) Error in dbGetResult.PgSQL.result(res) : ERROR: syntax error at or near "FROM" at character 8 > dbColumnInfo(res) Error in dbColumnInfo.PgSQL.result(res) : ERROR: syntax error at or near "FROM" at character 8 The diff below is against current SVN (meaning, this diff assumes that my change from yesterday is already there). Style-wise, maybe it ought to use a switch statement, or maybe now that there are four lines of identical code in two functions they should get factored into their own function. I don't think it matters much in this case--this message includes what I think is the minimal change, without any larger-scale refactoring. If anyone has a strong opinion about it (or any other comments), let me know and I'll re-do. Regards, Mitch Index: PgSQL.c =================================================================== --- PgSQL.c (revision 15600) +++ PgSQL.c (working copy) @@ -181,9 +181,12 @@ SEXP outFrame, rowNames, colNames; PGresult *result = (PGresult *) R_ExternalPtrAddr(resultPtr); - if (PQresultStatus(result) != PGRES_TUPLES_OK) + if (PQresultStatus(result) == PGRES_COMMAND_OK) error("Query did not produce any tuples"); + if (PQresultStatus(result) != PGRES_TUPLES_OK) + error(PQresultErrorMessage(result)); + rows = PQnfields(result); PROTECT(outFrame = allocVector(VECSXP, 3)); @@ -228,6 +231,9 @@ matrix = (int)LOGICAL(asMatrix)[0]; + if (PQresultStatus(result) == PGRES_COMMAND_OK) + error("Query did not produce any tuples"); + if (PQresultStatus(result) != PGRES_TUPLES_OK) error(PQresultErrorMessage(result));