如何在 laravel 中添加外键而不出错？

Question

你们能帮我吗？我想在 posts 表中添加一个外键，该外键在 categories 表中具有引用。但是当我输入命令 php artisan migrate:fresh 时它总是失败。我得到的错误是这样的 PDOException::("SQLSTATE[HY000]: General error: 1005 Can't create table 'handconsulting'.'posts' (errno: 150 "Foreignkey constrained is invalid Formed")")

这是我的 posts 表

 Schema::create('posts', function (Blueprint $table) {
            $table->id();
            $table->string('title');
            $table->foreignId('category_id')->constrained('categories')->onDelete('cascade')->onUpdate('cascade');
            $table->string('slug')->unique();
            $table->text('excerpt');
            $table->text('body');
            $table->string('iamge')->nullable();
            $table->timestamp('published_at')->nullable();
            $table->timestamps();
        });

这是我的 categories 表

Schema::create('categories', function (Blueprint $table) {
            $table->engine = 'InnoDB';
            $table->id();
            $table->string('name')->unique();
            $table->string('slug')->unique();
            $table->timestamps();
        });

Answer 1

这是我的方法：

$table->unsignedBigInteger('category_id');
$table->foreign('category_id')->references('id')->on('categories')->onDelete('cascade')->onUpdate('cascade');