Обсуждение: detecting NULL from libpq...

Hi.  I'm wondering if it's possible to tell whether a field returned
by PQgetvalue() is NULL?  Can one distinguish between a varchar field
that contains a string of zero length and a varchar field that is
NULL?  (And if so, how? :-)

regards,
d.

>
> Hi.  I'm wondering if it's possible to tell whether a field returned
> by PQgetvalue() is NULL?  Can one distinguish between a varchar field
> that contains a string of zero length and a varchar field that is
> NULL?  (And if so, how? :-)


From man libpq:

              PQgetisnull returns the NULL status of a field.
              int PQgetisnull(PGresult *res,
                              int tup_num,
                              int field_num);


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