Function create_upd_cascade_trg

src/gpre/cmd.cpp:607–687

//

static void create_upd_cascade_trg( gpre_req* request, const act* action,
								   cnstrt* constraint)
{
	gpre_lls* for_key_fld = constraint->cnstrt_fields;
	gpre_lls* prim_key_fld = constraint->cnstrt_referred_fields;
	gpre_rel* relation = (gpre_rel*) action->act_object;

	// no trigger name is generated here. Let the engine make one up
	put_string(request, isc_dyn_def_trigger, "", (USHORT) 0);

	put_numeric(request, isc_dyn_trg_type, (SSHORT) POST_MODIFY_TRIGGER);

	request->add_byte(isc_dyn_sql_object);
	put_numeric(request, isc_dyn_trg_sequence, (SSHORT) 1);
	put_numeric(request, isc_dyn_trg_inactive, (SSHORT) 0);
	put_cstring(request, isc_dyn_rel_name, constraint->cnstrt_referred_rel->str_string);

	// the trigger blr

	request->add_byte(isc_dyn_trg_blr);
	const USHORT offset = request->req_blr - request->req_base;

	request->add_word(0);
	if (request->req_flags & REQ_blr_version4)
		request->add_byte(blr_version4);
	else
		request->add_byte(blr_version5);

	create_trg_firing_cond(request, constraint);

	request->add_byte(blr_begin);
	request->add_byte(blr_begin);

	request->add_byte(blr_for);
	request->add_byte(blr_rse);

	// the new context for the prim. key relation
	request->add_byte(1);

	request->add_byte(blr_relation);
	put_cstring(request, 0, relation->rel_symbol->sym_string);
	// the context for the foreign key relation
	request->add_byte(2);

	// generate the blr for: foreign_key == primary_key
	create_matching_blr(request, constraint);

	request->add_byte(blr_modify);
	request->add_byte((SSHORT) 2);
	request->add_byte((SSHORT) 2);
	request->add_byte(blr_begin);

	for (; for_key_fld && prim_key_fld;
		 for_key_fld = for_key_fld->lls_next, prim_key_fld = prim_key_fld->lls_next)
	{
		const str* for_key_fld_name = (STR) for_key_fld->lls_object;
		const str* prim_key_fld_name = (STR) prim_key_fld->lls_object;