Problem with API (libpq) - detailed error codes

Hi!

I started programming PostgreSQL database with libpq API (client
side). It looks very easy, but unexpected I found problem, which I
cannot solve myself.
If function PQexec fails, I can get error code using PQresultStatus.
But returned codes are very generally and do not specify what really
happen. I can get detailed error description using PQerrorMessage
function, but I need detailed error code (number).

For instance, if I create table, I would like to know, that operation
failed because:
- table already exist
- sql syntax error
- invalid columnt type
and so on.

I searched documents about libpq API and even header file
'internal/libpq-int.h' but I didn't found any interesting.

I would be very gracefully for any hint.

Best regards,
Adam Bukla

re: Problem with API (libpq) - detailed error codes

Adam.Bukla@interia.pl wrote:[color=blue]
>...
>
> If function PQexec fails, I can get error code using PQresultStatus.
> But returned codes are very generally and do not specify what really
> happen. I can get detailed error description using PQerrorMessage
> function, but I need detailed error code (number).
>
> For instance, if I create table, I would like to know, that operation
> failed because:
> - table already exist
> - sql syntax error
> - invalid columnt type
> and so on.
>
> I searched documents about libpq API and even header file
> 'internal/libpq-int.h' but I didn't found any interesting.
>
> I would be very gracefully for any hint.[/color]

Appendix A of the PostgreSQL 7.4.1 Reference Manual has a list of error
codes (5 digit numbers) and their meanings. You get at the error code
with PQresultErrorField(result, PG_DIAG_SQLSTATE).

re: Problem with API (libpq) - detailed error codes

Adam.Bukla@interia.pl (Adam Bukla) writes:[color=blue]
> If function PQexec fails, I can get error code using PQresultStatus.
> But returned codes are very generally and do not specify what really
> happen. I can get detailed error description using PQerrorMessage
> function, but I need detailed error code (number).[/color]

Beginning in Postgres 7.4, there are standard SQLSTATE error codes
available (see PQresultErrorField), but older releases do not have them.

regards, tom lane

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re: Problem with API (libpq) - detailed error codes

Hi!

Thanks ljb and Tom Lane - it's exactly what I wanted.
I read documentation to 7.3 so I couldn't find PQresultErrorField function.
I'm suprised, that such necessary functionality exist only in 7.4 version.

Thanks once again,
Adam Bukla