php artisan 迁移外键错误

Question

主表 POll

 public function up()
    {
        Schema::create('poll', function (Blueprint $table) {
            $table->increments('id');
            $table->timestamps();
            $table->string('poll_question', 255);
            $table->boolean('status',1)->default(0)->index();
            $table->unsignedInteger('order');
        });
    }

明细表

  public function up()
    {
        Schema::create('poll_option', function (Blueprint $table) {
            $table->increments('id');
            $table->timestamps();
            $table->integer('poll_id');
            $table->string('poll_option', 255);
            $table->unsignedInteger('vote_poll_option');
            $table->unsignedInteger('order');
            $table->boolean('status',1)->default(0)->index();

            $table->foreign('poll_id')->references('id')->on('poll')->onUpdate('cascade')->onDelete('cascade');
        });
    }

当我使用外键运行 php artisan 时

SQLSTATE[HY000]: General error: 1005 Can't create table mydb.#sql-6f4_433 (errno: 150 "Foreign key constraint is incorrectly formed")

注意:我使用的是laravel 5.2，并且mysql类型已经是Innodb，导致错误形成的主要原因是什么

Answer 1

在详细信息表中

public function up()
    {
        Schema::create('poll_option', function (Blueprint $table) {
            $table->increments('id');
            $table->timestamps();
            $table->integer('poll_id')->unsigned(); //Change Here
            $table->string('poll_option', 255);
            $table->unsignedInteger('vote_poll_option');
            $table->unsignedInteger('order');
            $table->boolean('status',1)->default(0)->index();

            $table->foreign('poll_id')
              ->references('id')->on('poll')
              ->onDelete('CASCADE')
              ->onUpdate('CASCADE');
        });
    }

这对你有用