thinkphp5.1模型关联 -- 一对一关联

下面两个是关联表：test_user表和test_profile表，关联字段为：test_profile表中的user_id字段关联test_user表中的id字段

 模型：User.php中的代码如下：

<?php

namespace app\index\model;
use think\Model;

class User extends Model
{
    protected $table = 'test_user';
    protected $pk = 'id';
    
    //这里的方法名可以随意取，只要不冲突即可
    public function profile()
    {
        return $this->hasOne('Profile','user_id');
    }
}

 模型：Pofile.php中的代码如下：

<?php
namespace app\index\model;

use think\Model;

class Profile extends Model
{
    protected $table = 'test_profile';
    protected $pk = 'id';

    public function returnUser()
    {
        return $this->belongsTo('User','user_id');
    }

}

控制器index.php中的代码如下：

<?php
namespace app\index\controller;

use think\Controller;
use think\Db;
use app\index\model\User;
use app\index\model\Profile;

class Index extends Controller
{
    public function index()
    {
        /*对比以下两个查询方法，加深对一对一关联查询的理解*/

        //通过test_profile表中用户昵称是"及时雨"这个条件，查询test_user表中符合条件的数据
        $user = User::hasWhere('profile', ['nickname' => '及时雨'])->select();

        //通过test_user表中用户名是"李师师"这个条件，反过来查询test_profile表中符合条件的数据
        $pro = Profile::hasWhere('returnUser', ['username' => '李师师'])->select();

        //通过查询test_user表中id是7的记录，获取该条记录的用户昵称
        $pro2 = User::get(7);
        $nickname = $pro2->profile->nickname;//切记这里的$pro2->profile可千万不要写成了：$pro2->profile()。不能加括号，因为模型关联的时候，他相当于把profile当做了类的属性，虽然看上去是模型中的方法，但是他是按照获取属性的方式获取的

        echo '<pre>';
        print_r($user);
        print_r($pro);
        print_r($nickname);
    }

    public function index2()
    {
        //第一种：预载入查询
        $users = User::with('profile')->select();
        foreach ($users as $user) {
            echo $user->profile->nickname . '</br>';
        }
        /*
          产生的sql语句
         SELECT * FROM `test_user`
        SELECT * FROM `test_profile` WHERE  `user_id` IN (1,2,3,4,5,6,7,8)
         */

        

        //如果要对关联模型进行约束，可以使用闭包的方式。
        $users = User::with(['profile' => function ($query) {
            $query->where('nickname', '及时雨')->whereOr('nickname', '行者');
        }])->select();
        foreach ($users as $user) {
            echo $user->profile->nickname;
        }
        /**
        产生的sql语句
        SELECT * FROM `test_user`
        SELECT * FROM `test_profile` WHERE  `nickname` = '及时雨'  AND `user_id` IN (1,2,3,4,5,6,7,8) OR `nickname` = '行者'
         */

        

        //第二种：
        $users = User::select();
        foreach ($users as $user) {
            echo $user->profile->nickname . '</br>';
        }
        /*
         产生的sql语句
        SELECT * FROM `test_user`
        SELECT * FROM `test_profile` WHERE  `user_id` = 1 LIMIT 1
        SELECT * FROM `test_profile` WHERE  `user_id` = 2 LIMIT 1
        SELECT * FROM `test_profile` WHERE  `user_id` = 3 LIMIT 1
        SELECT * FROM `test_profile` WHERE  `user_id` = 4 LIMIT 1
        SELECT * FROM `test_profile` WHERE  `user_id` = 5 LIMIT 1
        SELECT * FROM `test_profile` WHERE  `user_id` = 6 LIMIT 1
        SELECT * FROM `test_profile` WHERE  `user_id` = 7 LIMIT 1
        SELECT * FROM `test_profile` WHERE  `user_id` = 8 LIMIT 1
         */
    }

    public function index3()
    {
        //第一种：预载入查询
        $users = User::with('profile')->select();
        foreach ($users as $user) {
            echo $user->profile->nickname . '</br>';
        }
        /*
          如果User.php中   return $this->hasOne('Profile','user_id')->setEagerlyType(0);
          或者 如果User.php中   return $this->hasOne('Profile','user_id');
          产生的sql语句
         SELECT * FROM `test_user`
        SELECT * FROM `test_profile` WHERE  `user_id` IN (1,2,3,4,5,6,7,8)
         */

        /*
         如果User.php中return $this->hasOne('Profile','user_id')->setEagerlyType(0);
         产生的sql语句
         SELECT `user`.`id`,`user`.`user_group_id`,`user`.`username`,`user`.`password`,`profile`.`id` AS `profile__id`,`profile`.`user_id` AS `profile__user_id`,`profile`.`nickname` AS `profile__nickname`,`profile`.`sex` AS `profile__sex` FROM `test_user` `user` INNER JOIN `test_profile` `profile` ON `user`.`id`=`profile`.`user_id`
         */

        //===================================================================//
        //使用withJoin()方法，就是用'join'方式，这
        $users = User::withJoin('profile')->select();
        foreach ($users as $user) {
            echo $user->profile->nickname . '</br>';
        }

        /**
         SELECT `user`.`id`,`user`.`user_group_id`,`user`.`username`,`user`.`password`,`profile`.`id` AS `profile__id`,`profile`.`user_id` AS `profile__user_id`,`profile`.`nickname` AS `profile__nickname`,`profile`.`sex` AS `profile__sex` FROM `test_user` `user` INNER JOIN `test_profile` `profile` ON `user`.`id`=`profile`.`user_id`
         */


        $users = User::withJoin('profile','LEFT')->select();
        foreach ($users as $user) {
            echo $user->profile->nickname . '</br>';
        }
        /**
         SELECT `user`.`id`,`user`.`user_group_id`,`user`.`username`,`user`.`password`,`profile`.`id` AS `profile__id`,`profile`.`user_id` AS `profile__user_id`,`profile`.`nickname` AS `profile__nickname`,`profile`.`sex` AS `profile__sex` FROM `test_user` `user` LEFT JOIN `test_profile` `profile` ON `user`.`id`=`profile`.`user_id`
         */

         //===================================================================//
        //$res = User::get(8)->profile->save(['nickname'=>'孝义','sex'=>'男']);//编辑操作
        $res = User::get(8)->profile()->save(['nickname'=>'孝义','sex'=>'男']);//新增操作
        var_dump($res);die;


         //===================================================================//
        //反过来，根据关联模型test_profile表的信息，获取test_user表的的对应的信息
        return Profile::get(7)->returnUser->username;

        
          //===================================================================//
        //模型绑定：就是在输出父模型数据表中的字段时，同时还输出绑定到父模型中的关联模型中的字段
        //如下：因为User.php中， return $this->hasOne('Profile','user_id')->bind('nickname');把'nickname'字段绑定到了父模型下，所以在输出父模型test_user表中的字段时，同时还会输出绑定到该模型下在test_profile表中的nickname字段
        $user = User::get(1, 'profile');
        echo '<pre>';
        print_r($user);
        echo $user->nickname;
        die;
    }