framework/db/BaseActiveRecord.php
public static function isPrimaryKey($keys)
    {
        $pks = static::primaryKey();
        if (count($keys) === count($pks)) {
            return count(array_intersect($keys, $pks)) === count($pks);
        }

        return false;
    }
public static function isPrimaryKey($keys)
    {
        $pks = static::primaryKey();
        if (count($keys) === count($pks)) {
            return count(array_intersect($keys, $pks)) === count($pks);
        }

        return false;
    }
Returns a value indicating whether the given set of attributes represents the primary key for this model.
@param array $keys the set of attributes to check
@return bool whether the given set of attributes represents the primary key for this model