以下是我嘗試按所述順序運行的兩個遷移。varitypes是相同的，我在制作表格后添加了FK，但它仍然給我帶來了1215 Cannot add foreign key constraint錯誤。一般錯誤 1215：無法為 Laravel 5 添加外鍵約束2019_12_10_130856_all_skillset.phppublic function up(){    Schema::create('all_skillsets', function(Blueprint $table){        $table->increments('id');        $table->char('skillset');    });}2019_12_10_300000_skillset.phppublic function up(){    Schema::create('skillsets', function(Blueprint $table){        $table->increments('id');        $table->unsignedInteger('spid');        $table->char('skill');    });    Schema::table('skillsets', function(Blueprint $table){        $table->foreign('skill')->references('skillset')->on('all_skillsets');        $table->foreign('spid')->references('id')->on('players');    });}