无法添加外键约束 - Laravel 委托

Question

我真的不知道哪里出了问题，但是我不能用这个查询添加外键约束。

alter table `__acc_role_user` add constraint `__acc_role_user_user_id_foreign` foreign key (`user_id`) references `__acc_accounts` (`account_id`) on delete cascade on update cascade

我如何创建帐户 table？

    Schema::create('__acc_accounts', function($table)
    {
        $table->integer('account_id')->increments();
        $table->integer('points')->default(0);

        $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
    });

然后Entrust Migration（下面只有有问题的部分）：

    Schema::create('__acc_role_user', function (Blueprint $table) {
        $table->integer('user_id')->unsigned();
        $table->integer('role_id')->unsigned();

        $table->foreign('user_id')->references('account_id')->on('__acc_accounts')
            ->onUpdate('cascade')->onDelete('cascade');
        $table->foreign('role_id')->references('id')->on('__acc_roles')
            ->onUpdate('cascade')->onDelete('cascade');

        $table->primary(['user_id', 'role_id']);
    });

Answer 1

这个语法更好：

/**
 * Run the migrations.
 *
 * @return void
 */
public function up()
{
    Schema::create('__acc_accounts', function($table)
    {
        $table->integer('account_id')->increments();
        $table->integer('points')->default(0);
    });

    Schema::table('__acc_accounts', function(Blueprint $table)
{
        $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
    });
}


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

而且非常重要！在你的迁移顺序中必须是：先创建table 'accounts'然后再创建'__acc_accounts'。

Tables with foreign keys should be created after the tables they reference to have been created.

这个http://blog.kongnir.com/2015/03/08/laravel-order-of-migrations-with-foreign-keys/可以帮助你理解这一点。

无法添加外键约束 - Laravel 委托

Cannot add foreign key constraint - Laravel Entrust

php

mysql

foreign-keys

laravel

entrust