php - 错误问题：1215 无法添加外键约束

Question

如何解决这个错误？SQLSTATE [HY000]：一般错误：1215 无法添加外键约束（SQL：删除级联时更改表invoices添加约束invoices_form_id_foreign外键（form_id）引用forms（ ））id

我得到它之后： php artisan migrate:fresh

对于发票中的外键，会出现此错误。3 个外键生成错误，但 user_id 的一个很好并且工作正常。我尝试了所有解决方案，但没有奏效。请帮我。

2014_10_12_000000_create_users_table.php

    <?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateUsersTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('users', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name');
            $table->string('email')->unique();
            $table->timestamp('email_verified_at')->nullable();
            $table->string('surname')->nullable();
            $table->string('showname')->nullable();
            $table->string('business')->nullable();
            $table->string('NIP')->nullable();
            $table->string('PESEL')->nullable();
            $table->string('address')->nullable();
            $table->string('city')->nullable();
            $table->string('postalcode')->nullable();
            $table->string('phone')->nullable();
            $table->string('comments')->nullable();
            $table->string('password');
            $table->rememberToken();
            $table->timestamps();
        });
    }

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

2020_07_23_104440_invoices.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class Invoices extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('invoices', function (Blueprint $table) {
            $table->increments('id');
            $table->string('invoicenumber')->nullable();
            $table->date('invoicedate')->nullable();
            $table->date('selldate')->nullable();
            $table->integer('user_id')->unsigned()->nullable();
            $table->integer('form_id')->unsigned()->nullable();                        
            $table->integer('currency_id')->unsigned()->nullable();
             
            $table->integer('proform_id')->unsigned()->nullable(); 
            $table->string('paymentmethod')->nullable();
            $table->date('paymentdate')->nullable();
            $table->string('status')->nullable();
            $table->string('comments')->nullable();
            $table->string('city')->nullable();
            $table->string('paid')->nullable();
            $table->string('autonumber')->nullable();
            $table->string('automonth')->nullable();
            $table->string('autoyear')->nullable();
            $table->timestamps();
        });
        
        Schema::table('invoices', function (Blueprint $table){
            $table->foreign('user_id')
                  ->references('id')
                  ->on('users');
            
            $table->foreign('form_id')
                  ->references('id')
                  ->on('forms');

            $table->foreign('currency_id')
                  ->references('id')
                  ->on('currencys');
            
            
            
            $table->foreign('proform_id')
                  ->references('id')
                  ->on('proforms');

        });
        
        
        
        
        
        
    }


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

2020_07_27_090356_proforms.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class Proforms extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('proforms', function (Blueprint $table) {
            $table->increments('id');
            $table->string('proformnumber')->nullable();
            $table->date('proformdate')->nullable();
            $table->date('selldate')->nullable();
            $table->integer('user_id')->unsigned()->nullable();
            $table->string('paymentmethod')->nullable();
            $table->date('paymentdate')->nullable();
            $table->string('status')->nullable();
            $table->string('comments')->nullable();
            $table->timestamps();
        });
        
        Schema::table('proforms', function (Blueprint $table){
            $table->foreign('user_id')
                  ->references('id')
                  ->on('users');
        });
        
        
        
        
        
        
    }


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

2020_07_28_091856_forms.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class Forms extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('forms', function (Blueprint $table) {
            $table->increments('id');
            $table->string('form')->nullable();
            $table->timestamps();
        });
    }

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

2020_07_28_091919_currencys.php

    <?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class Currencys extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('currencys', function (Blueprint $table) {
            $table->increments('id');
            $table->string('currency')->nullable();
            $table->string('course')->nullable();
            $table->timestamps();
        });
    }

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

标签： phpmysqlsqllaravelframeworks

Answer 1

以下是您的迁移可能发生的情况。

1.检查主键和外键类型。如果用户主键ID是type $table->increments('id'); // bigInteger，那么外键也应该是bigInteger $table->bigInteger('user_id')；

2.请检查您的迁移顺序。例如表invoices具有来自 的外键forms table。在迁移过程中，forms表应该首先迁移。为了让它发生，只需重命名迁移文件（文件名的数字部分），以便表格。