SQLSTATE[HY000]：一般错误：1215 无法添加外键约束 [Laravel 7.0]

Posted 2023-02-24

【中文标题】SQLSTATE[HY000]：一般错误：1215 无法添加外键约束 [Laravel 7.0]

【英文标题】：SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint [Laravel 7.0]

【发布时间】：2021-07-03 04:08:47

【问题描述】：

您好，当我尝试在 laravel 上迁移我的迁移时，我仍然收到此错误，我已经尝试了我在网上看到的所有建议，

错误是这个SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table settoris add constraint settoris_stock_code_foreign foreign key (stock_code) references prodottis (codice_stock) )

我得到了这个迁移，我不知道我做错了什么我正在使用 laravel 7 和 php 7.4

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

class CreateProdottisTable extends Migration

/**
 * Run the migrations.
 *
 * @return void
 */
public function up()

    Schema::create('prodottis', function (Blueprint $table) 
        $table->id();
        $table->unsignedBigInteger('codice_prodotto');
        $table->unsignedBigInteger('codice_stock');
        $table->date('data_di_scadenza');
        $table->decimal('costo', 10, 2);
        $table->timestamps();
    );


/**
 * Reverse the migrations.
 *
 * @return void
 */
public function down()

    Schema::dropIfExists('prodottis');

还有这个

<?php

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

class CreateSettorisTable extends Migration

/**
 * Run the migrations.
 *
 * @return void
 */
public function up()

    Schema::create('settoris', function (Blueprint $table) 
        $table->engine = 'InnoDB';
        $table->id();
        $table->unsignedBigInteger('stock_code');
        $table->string('settore');
        $table->string('scaffale');
        $table->integer('quantita_rimanente');
        $table->timestamps();
    );
    schema::table('settoris', function($table)
        $table->foreign('stock_code')->references('codice_stock')->on('prodottis');
    );


/**
 * Reverse the migrations.
 *
 * @return void
 */
public function down()

    Schema::dropIfExists('settoris');

【问题讨论】：

必须在references$table->foreign('stock_code')->references('codice_stock')->on('prodottis');中定义主键列

您需要在settoris 表之前迁移prodottis 表。

@Shahrukh 我已经做到了，

@EsTeAa 它在 settoris 之前迁移产品

【参考方案1】：

您正在将外键设置为引用不是 primary 键的 codice_stock 列。你可以这样primary index：

$table->unsignedBigInteger('codice_stock')->primary();

这样你会得到另一个错误！那是因为你只能有一个主键。所以你可以从prodottis 表中删除id。