Laravel Migrations - 列已存在

Question

我正在运行,Laravel Framework version 5.2.45并希望迁移我的数据库迁移.

我有两次迁移.一个是2014_10_12_100000_create_password_resets_table开箱即用的标准,另一个是我新创建的迁移2017_02_19_172350_create_keywords_table:

<?php

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateKeywordsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('keywords', function (Blueprint $table) {
            $table->increments('id');
            $table->string('keyword');
            $table->timestamps();
            $table->timestamps('published_at');

        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::drop('keywords');
    }
}

做php artisan migrate我喜欢的典型(回滚前):

root:~/workspace $ php artisan migrate:rollback
Rolled back: 2014_10_12_100000_create_password_resets_table
root:~/workspace $ php artisan migrate


  [Illuminate\Database\QueryException]                                                                                                                 
  SQLSTATE[42S21]: Column already exists: 1060 Duplicate column name 'created_at' (SQL: create table `keywords` (`id` int unsigned not null auto_incr  
  ement primary key, `keyword` varchar(255) not null, `created_at` timestamp null, `updated_at` timestamp null, `created_at` timestamp null, `updated  
  _at` timestamp null) default character set utf8 collate utf8_unicode_ci)                                                                             



  [PDOException]                                                                   
  SQLSTATE[42S21]: Column already exists: 1060 Duplicate column name 'created_at'  


root:~/workspace $ 

在数据库内部,不会keywords创建任何表.

有什么建议我做错了吗？

感谢您的回复!

Answer 1

$table->timestamps();是一个总是会添加created_at和updated_at字段的函数.在您的情况下,您将添加这两次.
如果要添加另一个时间戳字段,则必须使用该timestamp()功能.

所以你应该用published_at以下代码替换行(删除s):

$table->timestamp('published_at');

可以在文档中找到所有可能列类型的列表.