Function get_referred_fields

src/gpre/cmd.cpp:1130–1205

//

static void get_referred_fields(const act* action, cnstrt* constraint)
{
	TEXT s[512];
	const gpre_rel* relation = (gpre_rel*) action->act_object;

	for (gpre_req* req = gpreGlob.requests; req; req = req->req_next)
	{
		const act* request_action;
		const gpre_rel* rel;
		if (req->req_type == REQ_ddl && (request_action = req->req_actions) &&
			(request_action->act_type == ACT_create_table ||
				request_action->act_type == ACT_alter_table) &&
			(rel = (gpre_rel*) request_action->act_object) &&
			strcmp(rel->rel_symbol->sym_string, constraint->cnstrt_referred_rel->str_string) == 0)
		{
			for (const cnstrt* cns = rel->rel_constraints; cns; cns = cns->cnstrt_next)
			{
				if (cns->cnstrt_type == CNSTRT_PRIMARY_KEY)
				{
					constraint->cnstrt_referred_fields = cns->cnstrt_fields;
					break;
				}
			}
			if (!constraint->cnstrt_referred_fields && rel->rel_fields)
				for (const cnstrt* cns = rel->rel_fields->fld_constraints; cns; cns = cns->cnstrt_next)
				{
					if (cns->cnstrt_type == CNSTRT_PRIMARY_KEY)
					{
						constraint->cnstrt_referred_fields = cns->cnstrt_fields;
						break;
					}
				}
			if (constraint->cnstrt_referred_fields)
				break;
		}
	}

	if (constraint->cnstrt_referred_fields == NULL)
		// Nothing is in memory. Try to find in system tables
		constraint->cnstrt_referred_fields =
			MET_get_primary_key(relation->rel_database, constraint->cnstrt_referred_rel->str_string);

	if (constraint->cnstrt_referred_fields == NULL)
	{
		// Nothing is in system tables.
		sprintf(s,
				"\"REFERENCES %s\" without \"(column list)\" requires PRIMARY KEY on referenced table",
				constraint->cnstrt_referred_rel->str_string);
		CPR_error(s);
	}
	else
	{
		// count both primary key and foreign key columns
		USHORT prim_key_num_flds = 0, for_key_num_flds = 0;
		const gpre_lls* field = constraint->cnstrt_referred_fields;
		while (field)
		{
			prim_key_num_flds++;