Function create_matching_blr

src/gpre/cmd.cpp:513–575

//

static void create_matching_blr(gpre_req* request, const cnstrt* constraint)
{
	// count primary key columns
	const gpre_lls*  prim_key_fld = constraint->cnstrt_referred_fields;
	const gpre_lls* field = prim_key_fld;

	fb_assert(field != NULL);

	USHORT prim_key_num_flds = 0;
	while (field)
	{
		prim_key_num_flds++;
		field = field->lls_next;
	}

	fb_assert(prim_key_num_flds > 0);

	// count of foreign key columns
	const gpre_lls* for_key_fld = constraint->cnstrt_fields;
	field = for_key_fld;

	fb_assert(field != NULL);

	USHORT for_key_num_flds = 0;
	while (field)
	{
		for_key_num_flds++;
		field = field->lls_next;
	}

	fb_assert(for_key_num_flds > 0);
	fb_assert(prim_key_num_flds == for_key_num_flds);

	request->add_byte(blr_boolean);
	if (prim_key_num_flds > 1)
		request->add_byte(blr_and);

	USHORT num_flds = 0;

	do {
		request->add_byte(blr_eql);

		const str* for_key_fld_name = (STR) for_key_fld->lls_object;
		const str* prim_key_fld_name = (STR) prim_key_fld->lls_object;

		request->add_byte(blr_field);
		request->add_byte((SSHORT) 2);
		put_cstring(request, 0, for_key_fld_name->str_string);
		request->add_byte(blr_field);
		request->add_byte((SSHORT) 0);
		put_cstring(request, 0, prim_key_fld_name->str_string);

		++num_flds;

		if (prim_key_num_flds - num_flds >= 2)
			request->add_byte(blr_and);

		for_key_fld = for_key_fld->lls_next;