think\Model::belongsToMany PHP Method

    public function belongsToMany($model, $table = '', $foreignKey = '', $localKey = '', $alias = [])
    {
        // 记录当前关联信息
        $model = $this->parseModel($model);
        $name = Loader::parseName(basename(str_replace('\\', '/', $model)));
        $table = $table ?: $this->db()->getTable(Loader::parseName($this->name) . '_' . $name);
        $foreignKey = $foreignKey ?: $name . '_id';
        $localKey = $localKey ?: Loader::parseName($this->name) . '_id';
        return $this->relation()->belongsToMany($model, $table, $foreignKey, $localKey, $alias);
    }