public function joins($joins)
    {
        $this->joins = [];
        foreach ($joins as $join) {
            $j = [
                'table' => $this->trimName($join['table']),
                'on' => $join['on'],
                'type' => $join['type'],
            ];
            if (!empty($alias)) {
                $j['alias'] = $this->trimName($join['alias']);
            }
            $this->joins = array_merge($this->joins, [$join]);
        }
        return $this;
    }