Question

我想用多个外键创建一个表。这是sql：

CREATE TABLE `customers` (
    `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(50) DEFAULT NULL,
    `address` varchar(100) DEFAULT NULL,
    `email` varchar(50) DEFAULT NULL,
    `type_id` tinyint(3) unsigned DEFAULT NULL,
    `district_id` tinyint(3) unsigned DEFAULT NULL,
    `city_id` tinyint(3) unsigned DEFAULT NULL,
    `business_id` tinyint(3) unsigned DEFAULT NULL,
    `group_id` tinyint(3) unsigned DEFAULT NULL,
    PRIMARY KEY (`id`),
    KEY `FK_customer_1` (`district_id`,`city_id`),
    KEY `FK_customer_2` (`business_id`),
    KEY `FK_customer_3` (`group_id`),
    KEY `FK_customer_4` (`type_id`),
    CONSTRAINT `FK_customer_1` FOREIGN KEY (`district_id`, `city_id`)
    REFERENCES `cities` (`district_id`, `city_id`) ON DELETE CASCADE,
    CONSTRAINT `FK_customer_2` FOREIGN KEY (`business_id`) REFERENCES `businesses` (`business_id`) ON DELETE CASCADE,
    CONSTRAINT `FK_customer_3` FOREIGN KEY (`group_id`) REFERENCES `groups` (`group_id`) ON DELETE CASCADE,
    CONSTRAINT `FK_customer_4` FOREIGN KEY (`type_id`) REFERENCES `types` (`type_id`) ON DELETE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=latin1;

我用以下内容编写了一个迁移文件：

Schema::create('customers', function (Blueprint $table) {
    $table->increments('id');
    $table->string('name',50);
    $table->string('address',100)->nullable();
    $table->string('email',50)->nullable();
    $table->integer('type_id')->unsigned()->index();
    $table->integer('district_id')->unsigned()->index();
    $table->integer('city_id')->unsigned()->index();
    $table->integer('business_id')->unsigned()->index();
    $table->integer('group_id')->unsigned()->index();
    $table->timestamps();

    $table->foreign(['district_id','city_id'])->references(['district_id','city_id'])->on('cities')->onDelete('cascade');
    $table->foreign('business_id')->references('business_id')->on('businesses')->onDelete('cascade');
    $table->foreign('type_id')->references('type_id')->on('types')->onDelete('cascade');
    $table->foreign('group_id')->references('group_id')->on('groups')->onDelete('cascade');
});

但是当我运行迁移时，它给了我以下错误。

SQLSTATE[HY000]: General error: 1005 Can't create table `wastewater`.`#sql-5a8_18a` (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter table `customers` add constraint `customers_district_id_city_id_foreign` foreign key (`district_id`, `city_id`) references `cities` (`district_id`, `city_id`) on delete cascade)`

我该怎么办？

Answer 1

可以请这样尝试，只是删除数组并仅用逗号分隔来定义。

Schema::create('customers', function (Blueprint $table) {
    $table->increments('id');
    $table->string('name',50);
    $table->string('address',100)->nullable();
    $table->string('email',50)->nullable();
    $table->integer('type_id')->unsigned()->index();
    $table->integer('district_id')->unsigned()->index();
    $table->integer('city_id')->unsigned()->index();
    $table->integer('business_id')->unsigned()->index();
    $table->integer('group_id')->unsigned()->index();
    $table->timestamps();

    $table->foreign('district_id','city_id')->references('district_id','city_id')->on('cities','cities')->onDelete('cascade','cascade');
    $table->foreign('business_id')->references('business_id')->on('businesses')->onDelete('cascade');
    $table->foreign('type_id')->references('type_id')->on('types')->onDelete('cascade');
    $table->foreign('group_id')->references('group_id')->on('groups')->onDelete('cascade');
});

Answer 2

尝试以下方法，它将起作用。

Schema::create('customers', function (Blueprint $table) {
    $table->increments('id');

    $table->integer('type_id', false, true);
    $table->foreign('type_id')->references('type_id')->on('types')
        ->onDelete('cascade');

    $table->integer('district_id', false, true);
    $table->foreign('district_id')
        ->references('district_id')->on('cities')
        ->onDelete('cascade');

    $table->integer('city_id', false, true);
    $table->foreign('city_id')
        ->references('city_id')->on('cities')
        ->onDelete('cascade');

    $table->integer('business_id', false, true);
    $table->foreign('business_id')->references('business_id')
        ->on('businesses')->onDelete('cascade');

    $table->integer('group_id', false, true);
    $table->foreign('group_id')->references('group_id')->on('groups')
        ->onDelete('cascade');
            $table->string('name',50);
    $table->string('address',100)->nullable();
    $table->string('email',50)->nullable();
    $table->timestamps();
});

如何为具有多个外键的表创建laravel迁移？

2 个答案: