无法创建Laravel迁移文件2的外键

Question

我正在尝试创建一个新表，其中2个外键将被设置为

public function up()
{
Schema::create('role_permissions_link', function (Blueprint $table) {
$table->id();
$table->integer('permissions_id')->unsigned();
$table->integer('users_role_id')->unsigned();
$table->timestamps();
$table->index(['permissions_id', 'users_role_id']);
});
Schema::table('role_permissions_link', function (Blueprint $table) {
$table->foreign('permissions_id')->references('id')->on('permissions');
$table->foreign('users_role_id')->references('id')->on('users_role');
});
}

我一直在说

SQLSTATE[HY000]: General error: 1005 Can't create table `homestead`.`ja_role_permissions_link` (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter table `ja_role_permissions_link` add constraint `ja_role_permissions_link_permissions_id_foreign` foreign key (`permissions_id`) references `ja_permissions` (`id`))
at vendor/laravel/framework/src/Illuminate/Database/Connection.php:669
665|         // If an exception occurs when attempting to run a query, we'll format the error
666|         // message to include the bindings with SQL, which will make this exception a
667|         // lot more helpful to the developer instead of just the database's errors.
668|         catch (Exception $e) {
> 669|             throw new QueryException(
670|                 $query, $this->prepareBindings($bindings), $e
671|             );
672|         }
673| 
+9 vendor frames 
10  database/migrations/2020_04_06_144324_create_role_permissions_link_table.php:27
IlluminateSupportFacadesFacade::__callStatic()
+34 vendor frames 
45  artisan:37
IlluminateFoundationConsoleKernel::handle()

我尝试过移动代码和一些在线解决方案，但总是出现同样的错误。

权限迁移文件

public function up()
{
Schema::create('permissions', function (Blueprint $table) {
$table->id();
$table->string('name');
$table->timestamps();
$table->index(['id']);
});
}

users_role迁移文件

public function up()
{
Schema::create('users_role', function (Blueprint $table) {
$table->id();
$table->string('name');
$table->timestamps();
$table->index(['id']);
});
}

Answer 1

解决方案1-数据类型~(这次不行！(~~

需要检查的是列和键的数据类型是否匹配。

如果一个表上的外键(即$table->integer('permissions_id')->unsigned();(与另一个表($table->bigIncrements('id');(上的id不匹配，则会出现此错误

---

解决方案2-迁移顺序(正确(

permissions应该在role_permissions之前。您可能需要稍微重命名迁移，因为它们将根据名称按日期顺序运行。