迁移的外键问题

Question

我正在使用软件包https://github.com/musonza/groups在laravel应用中添加组系统，但是当我要迁移时，出现错误消息：

Migration table created successfully.
Migrating: 2019_05_26_125854_create_groups_tables

   Illuminate\Database\QueryException  : SQLSTATE[HY000]: General error: 1005 Can't create table `groupsystem`.`#sql-2678_26` (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter table `groups` add constraint `groups_user_id_foreign` foreign key (`user_id`) references `users` (`id`) on delete cascade)

这是我的2个迁移表代码：

<?php

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

class CreateUsersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('users', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name');
            $table->string('email')->unique();
            $table->timestamp('email_verified_at')->nullable();
            $table->string('password');
            $table->rememberToken();
            $table->timestamps();
        });
    }

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

这也是我从安装软件包中获得的迁移表： 我在这篇文章顶部的链接中提到的 这是我第一次尝试使用该软件包 我试图在我的laravel应用程序上创建一个组系统 任何其他建议都将受到欢迎

<?php

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

class CreateGroupsTables extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('groups', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->string('description')->nullable();
            $table->string('short_description')->nullable();
            $table->string('image')->nullable();
            $table->string('url')->nullable();
            $table->integer('user_id')->unsigned();
            $table->boolean('private')->unsigned()->default(false);
            $table->integer('conversation_id')->unsigned()->nullable();
            $table->text('extra_info')->nullable();
            $table->text('settings')->nullable();
            $table->timestamps();

            $table->foreign('user_id')
                ->references('id')
                ->on('users')
                ->onDelete('cascade');
        });

        Schema::create('group_user', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('user_id')->unsigned();
            $table->integer('group_id')->unsigned();
            $table->timestamps();

            $table->foreign('user_id')
                ->references('id')
                ->on('users')
                ->onDelete('cascade');

            $table->foreign('group_id')
                ->references('id')
                ->on('groups')
                ->onDelete('cascade');
        });

        Schema::create('posts', function (Blueprint $table) {
            $table->increments('id');
            $table->string('title');
            $table->text('body');
            $table->string('type');
            $table->integer('user_id')->unsigned();
            $table->text('extra_info')->nullable();
            $table->timestamps();

            $table->foreign('user_id')
                ->references('id')
                ->on('users')
                ->onDelete('cascade');
        });

        Schema::create('comments', function (Blueprint $table) {
            $table->increments('id');
            $table->string('body');
            $table->integer('user_id')->unsigned();
            $table->integer('post_id')->unsigned();
            $table->string('type')->nullable();
            $table->timestamps();

            $table->foreign('user_id')
                ->references('id')
                ->on('users');

            $table->foreign('post_id')
                ->references('id')
                ->on('posts');
        });

        Schema::create('group_post', function (Blueprint $table) {
            $table->integer('group_id')->unsigned();
            $table->integer('post_id')->unsigned();
            $table->timestamps();

            $table->foreign('group_id')
                ->references('id')
                ->on('groups')
                ->onDelete('cascade');

            $table->foreign('post_id')
                ->references('id')
                ->on('posts')
                ->onDelete('cascade');
        });

        Schema::create('likes', function (Blueprint $table) {
            $table->integer('user_id')->index();
            $table->integer('likeable_id')->unsigned();
            $table->string('likeable_type');
            $table->primary(['user_id', 'likeable_id', 'likeable_type']);
            $table->timestamps();
        });

        Schema::create('reports', function (Blueprint $table) {
            $table->integer('user_id')->index();
            $table->integer('reportable_id')->unsigned();
            $table->string('reportable_type');
            $table->primary(['user_id', 'reportable_id', 'reportable_type']);
            $table->timestamps();
        });

        Schema::create('group_request', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('user_id')->unsigned()->index();
            $table->integer('group_id')->unsigned()->index();
            $table->timestamps();

            $table->foreign('group_id')
                ->references('id')
                ->on('groups')
                ->onDelete('cascade');

            $table->foreign('user_id')
                ->references('id')
                ->on('users')
                ->onDelete('cascade');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::drop('groups');
        Schema::drop('group_user');
        Schema::drop('posts');
        Schema::drop('comments');
        Schema::drop('group_post');
        Schema::drop('likes');
        Schema::drop('reports');
        Schema::drop('group_request');
    }
}

Answer 1

我确实找到了解决方案，这是因为新的Laravel 5.8.3附带了unsignedBigInteger（id）而不是增量（id）

Answer 2

如果您使用过laravel 5.8，则

$table->unsignedBigInteger('user_id');
$table->foreign('user_id')->references('id')->on('users');

如果您使用过laravel <5.8，那么

$table->unsignedInteger('user_id');
$table->foreign('user_id')->references('id')->on('users');