Re: [GENERAL] Lifetime of PQexecPrepared() returned value

Igor Korot <ikorot01@gmail.com> writes:
> I have a following piece of code:

> [code]
> PGresult *res = PQexecPrepared();
> status = PQresultStatue( res );
> if( status == PGRES_TUPLES_OK )
> {
>     for( int j = 0; j < PQntuples( res ); j++ )
>     {
>         char *foo = PQgetValue( res, j, 0 );
>         char *bar = PQgetValue( res, j, 1 );
>         MyObject *obj = new MyObject( foo, bar );
>         if( SetAdditionalProperties( obj ) )
>         {
>               result = 1;
>               break;
>         }
>     }
>     PQclear( res );
> }

What I'm wondering about is whether the MyObject constructor is making
copies of the strings it's passed, or whether it thinks it can just hold
onto those pointers.  The pointers would be dangling once you do PQclear.
Now, if the MyObject has gone out of scope and been destroyed, which
this coding suggests would happen, then that shouldn't matter ... but
maybe the pointers got copied to somewhere longer-lived?  Anyway, there's
nothing visibly wrong with what you showed us, so the problem is somewhere
else.

            regards, tom lane