laravel入门-mysql一对多

 

1. 创建user和Job的model

1 php artisan make:migration  order -m
2 
3 php artisan make:migration  user -m

 

2. 修改表结构Migration

 1 cat create_user_table.php
 2 
 3  public function up()
 4     {
 5         Schema::create('users', function (Blueprint $table) {
 6             $table->increments('id');
 7             $table->string("username",50);
 8             $table->string("age",3);
 9             $table->string("email",50);
10             $table->timestamps();
11         });
12     }
13 
14 cat create_order_table.php
15 
16 Schema::create('orders', function (Blueprint $table) {
17             $table->increments('id');
18             $table->unsignedInteger("user_id");
19             $table->string("name",50);
20             $table->string("describe",5000);
21             $table->foreign("user_id")
22                     ->references("id")->on("users")
23                     ->onDelete("cascade");
24             $table->timestamps();
25         });

 

3.  models 定义

 1 cat User.php
 2 
 3 <?php
 4 
 5 namespace App;
 6 
 7 use Illuminate\Database\Eloquent\Model;
 8  9 
10 class User extends Model
11 {
12     //要显示哪些列
13     protected $fillable = [
14         'username','age','email'
15     ];
16 
17 
18     function userTo()
19     {
20     return $this->hasMany('App\Order');
21     } 
22 
23 }
24 
25 
26 // 里面定义了user 和 order的一对多的关系

 

 

4. 控制器

 

 1   cat WeclomeController.php
 2 
 3    $u = User::find(1);
 4    return response($u->userTo);
 5     
 6 
 7 /*
 8 跨域解决
 9    $response = response('')
10               ->header('Access-Control-Allow-Origin', '*')
11              ->header('Access-Control-Allow-Headers', 'Origin, Content-Type, Cookie, Accept, multipart/form-data, application/json')
12              ->header('Access-Control-Allow-Methods', 'GET, POST')
13               ->header('Access-Control-Allow-Credentials', 'false');
14   
15 */

 

 

5. 常用的sql命令

3.1 删除索引
    alter table `job` drop index job_user_id_foreign ;

3.2 增加索引
    create unique index u_job_index on job(user_id) ;
    create index u_job_index on job(user_id) ;

3.3 增加外键
    alter table `job` add constraint `job_user_id_foreign` foreign key (`user_id`) references `users` (`id`) on delete cascade ;

3.4 删除外键
    alter table `job` drop foreign key job_user_id_foreign ;

 

posted @ 2018-12-11 14:06  追求那份真  阅读(270)  评论(0)  编辑  收藏  举报