SQLSTATE[HY000]：一般错误：1215 无法添加外键约束 laravel 9

发布于 2025-01-09 19:07:36 字数 703 浏览 2 评论 0原文

尝试分配外键，但是当您运行迁移时，我收到此错误，我不明白问题是什么。

SQLSTATE[HY000]：一般错误：1215 无法添加外键约束（SQL：alter table categories 添加约束categories_parent_key_foreign 外键（parent_key) 在删除级联上引用categories (key)

$table->bigIncrements('id');
$table->string('key', 64)->unique();
$table->string('parent_key', 64)->nullable()->index();
$table->string('title', 256)->index()->unique();
$table->foreign('parent_key')->references('key')
                ->on((new Category())->getConnection()->getDatabaseName() . '.' . Category::TABLE)
                ->onDelete('cascade');

原文

Trying to assign foreign key but when you run migrate, I get this this error, I do not understand what the problem is.

SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table categories add constraint categories_parent_key_foreign foreign key (parent_key) references categories (key) on delete cascade)

$table->bigIncrements('id');
$table->string('key', 64)->unique();
$table->string('parent_key', 64)->nullable()->index();
$table->string('title', 256)->index()->unique();
$table->foreign('parent_key')->references('key')
                ->on((new Category())->getConnection()->getDatabaseName() . '.' . Category::TABLE)
                ->onDelete('cascade');

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亣腦蒛氧 2025-01-16 19:07:36

我也有同样的问题。
当模型与其自身存在关系（自关系）时，就会出现问题。
要解决这个问题，首先必须创建迁移文件，然后必须在另一个迁移文件中分配外键。
您必须从迁移文件中删除外键分配，然后创建新的迁移文件，然后添加关系语句来分配外键。（迁移文件的顺序很重要）。

create_category_table

public function up(): void
{
    $table->bigIncrements('id');
    $table->string('key', 64)->unique();
    $table->string('parent_key', 64)->nullable()->index();
    $table->string('title', 256)->index()->unique();

}

create_category_relation_table

public function up(): void
{
    $table->foreign('parent_key')->references('key')
            ->on((new Category())->getConnection()->getDatabaseName() . '.' . Category::TABLE)
            ->onDelete('cascade');
}

然后 php artisan 迁移

I had the same problem.
The problem arises when a model has a relationship with itself (self-relation).
To solve this problem, first, the migration file must be created and then the foreign key must be assigned in another migration file.
You must remove the foreign key assignment from the migration file and create the new migration file after that, then add relations statements to assign a foreign key. (the order of the migration files is important).

create_category_table

public function up(): void
{
    $table->bigIncrements('id');
    $table->string('key', 64)->unique();
    $table->string('parent_key', 64)->nullable()->index();
    $table->string('title', 256)->index()->unique();

}

create_category_relation_table

public function up(): void
{
    $table->foreign('parent_key')->references('key')
            ->on((new Category())->getConnection()->getDatabaseName() . '.' . Category::TABLE)
            ->onDelete('cascade');
}

And then php artisan migration

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