Question

我正在尝试编写具有外部关系的laravel数据库迁移。在数据库迁移期间抛出查询异常错误。

我厌倦了使用laravel规则迁移表，但是在迁移过程中却显示了意外错误。

用户表

    Schema::create('users', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('name', 150);
        $table->string('email', 150)->unique();
        $table->timestamp('email_verified_at')->nullable();
        $table->string('phone', 150);
        $table->unsignedBigInteger('role_id');
        $table->foreign('role_id')->references('id')->on('roles')->onDelete('cascade');
        $table->string('password');
        $table->rememberToken();
        $table->timestamps();
    });

角色表

    Schema::create('roles', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('role_name',255);
        $table->longText('role_description',255);
        $table->integer('sort_order');
        $table->enum('status',['A','I','D'])->comment('A-active','I-inactive,D-delete'); 
        $table->enum('is_deleted',['Y','N'])->comment('Y-yes,N-no');
        $table->timestamps();
        $table->bigInteger('created_by');
        $table->bigInteger('updated_by')->default(0);
        $table->bigInteger('deleted_by')->default(0);
        $table->timestamp('deleted_at')->nullable();
    });

Illuminate \ Database \ QueryException：SQLSTATE [HY000]：常规错误： 1215无法添加外键约束（SQL：更改表jt_users 添加约束users_role_id_foreign外键（role_id）在删除级联上引用jt_roles（id）

Answer 1

您不能将外键添加到不存在的表中。对于您而言，您正在尝试创建role_id表之前创建一个roles。

在roles表迁移中，一旦创建了users表，您将需要更新roles表：

Schema::create('roles', function (Blueprint $table) {
    $table->bigIncrements('id');
    $table->string('role_name',255);
    $table->longText('role_description',255);
    $table->integer('sort_order');
    $table->enum('status',['A','I','D'])->comment('A-active','I-inactive,D-delete'); 
    $table->enum('is_deleted',['Y','N'])->comment('Y-yes,N-no');
    $table->timestamps();
    $table->bigInteger('created_by');
    $table->bigInteger('updated_by')->default(0);
    $table->bigInteger('deleted_by')->default(0);
    $table->timestamp('deleted_at')->nullable();
});

Schema::table('users', function (Blueprint $table) {
    $table->unsignedBigInteger('role_id');
    $table->foreign('role_id')->references('id')->on('roles')->onDelete('cascade');
});

注意：在更改表时，请使用Schema::table()代替Schema::create()。

在down()迁移的roles方法上，您需要删除外键和字段：

Schema::table('users', function (Blueprint $table) {
    $table->dropForeign(['role_id']);
    $table->dropColumn('role_id');
});

Answer 2

首先，必须迁移具有“主键”（用户）的表

Laravel迁移引发数据库查询异常错误

2 个答案: