<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2016 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think\model\relation;

use think\Model;
use think\model\relation\OneToOne;

class BelongsTo extends OneToOne
{
    /**
     * 架构函数
     * @access public
     * @param Model  $parent 上级模型对象
     * @param string $model 模型名
     * @param string $foreignKey 关联外键
     * @param string $otherKey 关联主键
     * @param array  $alias 别名定义
     * @param string $joinType JOIN类型
     */
    public function __construct(Model $parent, $model, $foreignKey, $localKey, $alias = [], $joinType = 'INNER')
    {
        $this->parent     = $parent;
        $this->model      = $model;
        $this->foreignKey = $foreignKey;
        $this->localKey   = $localKey;
        $this->alias      = $alias;
        $this->joinType   = $joinType;
        $this->query      = (new $model)->db();
    }

    /**
     * 延迟获取关联数据
     * @access public
     */
    public function getRelation()
    {
        $foreignKey = $this->foreignKey;
        $localKey   = $this->localKey;
        return $this->query->where($localKey, $this->parent->$foreignKey)->find();
    }

}