>void *PQinstanceData(const PGconn *conn, PGEventProc proc);</PRE
><P>
      </P
></DD
><DT
><A
NAME="LIBPQ-PQRESULTSETINSTANCEDATA"
></A
><CODE
CLASS="FUNCTION"
>PQresultSetInstanceData</CODE
>
      </DT
><DD
><P
>       Sets the result's <TT
CLASS="LITERAL"
>instanceData</TT
>
       for <TT
CLASS="PARAMETER"
>proc</TT
> to <TT
CLASS="PARAMETER"
>data</TT
>.  This returns
       non-zero for success and zero for failure.  (Failure is only
       possible if <TT
CLASS="PARAMETER"
>proc</TT
> has not been 