Question

您好我想创建一个外键但没有任何效果，我不明白为什么enter image description here

Answer 1

请提供有关表类型的更多信息，现在根据您键入的信息我可以建议您检查是否使用InnoDB表？在表1中对应于PK的表1中的FOREIGN KEY？他们有相同的类型和长度吗？

Answer 2

根据documentation，外键的正确语法是 s 。

Laravel表名通常也是复数，因此检查category也是正确的。

$table->foreign('category')->references('id')->on('category');

Answer 3

文章表

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

class CreateArticlesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('articles', function (Blueprint $table) {
            $table->increments('id');
            $table->string('title' , 255);
            $table->text('content');
            $table->integer('user_id')->unsigned();
            $table->foreign('user_id')->references('id')->on('users');
            $table->timestamps();
        });
    }

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

类别表

<?php

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

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

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

Laravel SQLSTATE [42000]：语法错误或访问冲突：1064

3 个答案: