Обсуждение: libpq PQexecPrepared returns NULL but all ok

PQexecPrepared returns NULL when execute an update statement, but update finish successfully and PQerrorMessage
returnanempty string. I sow similar problem here: http://archives.postgresql.org/pgsql-interfaces/2004-03/msg00003.php
butwithoutsolution. What do you think about it? 
I use static libpq.lib built from 8.1.4 source with nmake.

--
С уважением,Golikov                          mailto:golikov@eltrast.ru

Golikov Alexandr <golikov@eltrast.ru> writes:
>  PQexecPrepared returns NULL when execute an update statement, but update finish successfully and PQerrorMessage
return
>  an empty string.

Test case please?
        regards, tom lane