"VEN" <bsditer(at)gmail(dot)com> writes:
> Database have below table:
> CREATE TABLE TEST {
> NUM BIGINT NOT NULL DEFAULT 0
> };
> EXEC "SELECT NUM FROM TEST LIMIT 1"
> PQgetlength return valid length (sizeof(int64)), it's ok.
> but
> EXEC "SELECT SUM(NUM)::BIGINT FROM TEST"
> or
> EXEC "SELECT SUM(NUM) FROM TEST"
> PQgetlength already return zero.
I see no bug here. For such a case (with no rows in the table)
SUM() is defined to return NULL, and PQgetvalue() is defined to
return an empty string for a null, and PQgetlength() is defined
to return the length of whatever PQgetvalue() returns.
regards, tom lane