Re: C Language Stored Procedure Returning No Data - Mailing list pgsql-general

From Jeff Trout
Subject Re: C Language Stored Procedure Returning No Data
Date
Msg-id 48DFCEDF-B290-40DC-910E-71E04BE14374@torgo.978.org
Whole thread Raw
In response to Re: C Language Stored Procedure Returning No Data  (Michael Fuhr <mike@fuhr.org>)
Responses Re: C Language Stored Procedure Returning No Data  (Michael Fuhr <mike@fuhr.org>)
List pgsql-general
On Feb 2, 2006, at 7:17 PM, Michael Fuhr wrote:

> On Wed, Feb 01, 2006 at 12:56:30PM -0500, bfraci@aol.com wrote:
>> From a C stored procedure, how can I tell Postgres to pass on to
>> the Java client that there is No Data? A zero length byte array or
>> a null value is not the same as No Data.
>
> If you declare the function with "RETURNS bytea" then the function
> must return something; if zero-length data and NULL aren't suitable
> for indicating no data then you could raise an error and catch that
> error in the client.  Another possibility would be to make the
> function set-returning ("RETURNS SETOF bytea" and some code changes)
> and return no rows to indicate no data.


Another possibility is to log an exception with elog & company.
However that will also have the side effect of rolling back the txn
if you are currently in one.

--
Jeff Trout <jeff@jefftrout.com>
http://www.jefftrout.com/
http://www.stuarthamm.net/



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