Laravel Migrations

0 目的

创建Migrations主要的功能是为了让团队能保住使用的数据库结构一致

1 开玩

  1. 相关的命令(php artisan list)

     migrate:install     Create the migration repository
 migrate:refresh     Reset and re-run all migrations
 migrate:reset       Rollback all database migrations
 migrate:rollback    Rollback the last database migration
 migrate:status      Show the status of each migration

    创建数据库表(手动创建表不会作用.),因为输入命令后,会在verdor/composer/autoload_classmap.php里映射类.如下

         'Create_Disease_Type' => $baseDir . '/database/migrations/2015_11_02_153746_Create_Disease_Type.php',
     'CreateInstitutes' => $baseDir . '/database/migrations/2015_11_02_143144_Create_Institutes.php',

 php artisan make:migration Create_Users --create=Users

  2. 创建基础类,设置id、时间戳和软删除.

    一开始自己创建了个Base_Table,不过那样也会创建一个表,所以直接把方法写在Migration里

     /**
 * 增加基本属性
 * @param Blueprint $table
 */
 public function add_base_attribute(Blueprint $table)
 {
     $table->increments('id');
     //创建created_at和updated_at
     $table->timestamps();
     //创建deleted_at
     $table->softDeletes();
     return $table;
 }

  3. 创建外键,注意要先定义外键属性,再设定关系.

     public function up()
 {
     Schema::create('Institutes', function (Blueprint $table) {
         $table->unsignedInteger('institute_ID');
         $table->foreign('institute_ID')
         ->references('id')->on('institutes')
         ->onDelete('cascade');
         $table = parent::add_base_attribute($table);
     });
 }

  4. 修改表

     php artisan make:migration Add_Name_To_Samples_Table --table=Samples

 注意,要是新增列,直接和创建表一样语法

 但要修改已由列需要调用change()方法,例如:

      $table->string('name', 50)->change();

    可能报不是dba的错误

     [RuntimeException]
 Changing columns for table "Samples" requires Doctrine DBAL; install "doctrine/dbal".

    在composer.json中配置

     "require": {
     ...
     "doctrine/dbal": "v2.4.2"
 },

错误处理

  1. 有依赖关系的表,要把外键的表先创建.

  2. 外键的属性类型要一致,否则会报错General error: 1215 Cannot add foreign key constraint

     //主表
 $table->increments('id');

 //从表
 $table->unsignedInteger('institute_ID');
     $table->foreign('institute_ID')
     ->references('id')->on('institutes')
     ->onDelete('cascade');      the

  3. migrations类名不过有下划线

    报错

     PHP Fatal error:  Class 'CreateInstitutes' not found in /Users/maizhikun/Learning/apache_sites/HapLab_Laravel/vendor/laravel/framework/src/Illuminate/Database/Migrations/Migrator.php on line 324

 [Symfony\Component\Debug\Exception\FatalErrorException]
 Class 'CreateInstitutes' not found

 //看了下报错地方的源代码.估计是下划线导致.   
 public function resolve($file)
 {
     $file = implode('_', array_slice(explode('_', $file), 4));
     $class = Str::studly($file);
     return new $class;
 }

    后来又发现了错误.最后确定了是文件名(假如有下划线)会去掉下划线(从时间之后的下划线)然后找相对应的类名.

  4. php artisan migrate:refresh,reset,rollback都无法执行

    提示报错

     [Symfony\Component\Debug\Exception\FatalErrorException]
  Class 'Illuminate\Database\Migrations\Schema' not found

    解决办法:

    将Illuminate\Support\Facades\Schema复制到Illuminate\Database\Schema

    并且

    修改命名空间和use

     namespace Illuminate\Database\Migrations;

 use Illuminate\Support\Facades\Facade;

    参考

php

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