Function PQsetResultAttrs

src/interfaces/libpq/fe-exec.c:257–296

* PQsetResultAttrs * * Set the attributes for a given result. This function fails if there are * already attributes contained in the provided result. The call is * ignored if numAttributes is zero or attDescs is NULL. If the * function fails, it returns zero. If the function succeeds, it * returns a non-zero value. */

 * returns a non-zero value.
 */
int
PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs)
{
	int			i;

	/* If attrs already exist, they cannot be overwritten. */
	if (!res || res->numAttributes > 0)
		return false;

	/* ignore no-op request */
	if (numAttributes <= 0 || !attDescs)
		return true;

	res->attDescs = (PGresAttDesc *)
		PQresultAlloc(res, numAttributes * sizeof(PGresAttDesc));

	if (!res->attDescs)
		return false;

	res->numAttributes = numAttributes;
	memcpy(res->attDescs, attDescs, numAttributes * sizeof(PGresAttDesc));

	/* deep-copy the attribute names, and determine format */
	res->binary = 1;
	for (i = 0; i < res->numAttributes; i++)
	{
		if (res->attDescs[i].name)
			res->attDescs[i].name = pqResultStrdup(res, res->attDescs[i].name);
		else
			res->attDescs[i].name = res->null_field;

		if (!res->attDescs[i].name)
			return false;

		if (res->attDescs[i].format == 0)
			res->binary = 0;
	}

	return true;
}

/*
 * PQcopyResult