think\model\Relation::__call PHP Метод

    public function __call($method, $args)
    {
        if ($this->query) {
            switch ($this->type) {
                case self::HAS_MANY:
                    if (isset($this->where)) {
                        $this->query->where($this->where);
                    } elseif (isset($this->parent->{$this->localKey})) {
                        // 关联查询带入关联条件
                        $this->query->where($this->foreignKey, $this->parent->{$this->localKey});
                    }
                    break;
                case self::HAS_MANY_THROUGH:
                    $through = $this->middle;
                    $model = $this->model;
                    $alias = Loader::parseName(basename(str_replace('\\', '/', $model)));
                    $throughTable = $through::getTable();
                    $pk = (new $this->model())->getPk();
                    $throughKey = $this->throughKey;
                    $modelTable = $this->parent->getTable();
                    $this->query->field($alias . '.*')->alias($alias)->join($throughTable, $throughTable . '.' . $pk . '=' . $alias . '.' . $throughKey)->join($modelTable, $modelTable . '.' . $this->localKey . '=' . $throughTable . '.' . $this->foreignKey)->where($throughTable . '.' . $this->foreignKey, $this->parent->{$this->localKey});
                    break;
                case self::BELONGS_TO_MANY:
                    // TODO
            }
            $result = call_user_func_array([$this->query, $method], $args);
            if ($result instanceof \think\db\Query) {
                return $this;
            } else {
                return $result;
            }
        } else {
            throw new Exception('method not exists:' . __CLASS__ . '->' . $method);
        }
    }