Need help with libpq and PQexec

[Juan Backson <juanbackson@xxxxxxxxx>]

Hi,
In my source code, I have:

res = PQexec(conn,"select * from resource"); 
if(PQresultStatus(res) != PGRES_COMMAND_OK){ 
            switch_log_printf(SWITCH_CHANNEL_LOG,SWITCH_LOG_ERROR,"PQexec failed:%s\n",PQerrorMessage(conn)); 
            PQclear(res); 
            return NULL;
        } 
        PQclear(res); 

When it is executed, I am getting PGexec failed error , but the return value of  PQerrorMessage(conn) is empty.

Does anyone know why?

Thanks,
JB