Laravel 5遷移標識符名稱太長

Question

我試圖運行以下遷移：

public function up() 
{ 
    Schema::create('lifestyle_questions', function(Blueprint $table) 
    { 
     $table->increments('id'); 
     $table->string('question'); 
     $table->timestamps(); 
    }); 

    Schema::create('lifestyle_question_answers', function(Blueprint $table) 
    { 
     $table->increments('id'); 
     $table->integer('lifestyle_question_id')->unsigned(); 
     $table->foreign('lifestyle_question_id')->references('id')->on('lifestyle_questions'); 
     $table->string('answer'); 
     $table->timestamps(); 
    }); 

    Schema::create('user_lifestyle_question_answers', function(Blueprint $table) 
    { 
     $table->integer('user_id')->unsigned(); 
     $table->foreign('user_id')->references('id')->on('users'); 
     $table->integer('lifestyle_question_answer_id')->unsigned(); 
     $table->foreign('lifestyle_question_answer_id')->references('id')->on('lifestyle_question_answers'); 
    }); 
} 

，但我得到了以下錯誤：

[Illuminate\Database\QueryException] 
SQLSTATE[42000]: Syntax error or access violation: 1059 Identifier name 'user_lifestyle_question_answers_lifestyle_question_answer_id_foreign' is too long (SQL: alter table `user_lifestyle_question_answers` add constraint user_lifestyle_question_answers_lifestyle_question_answer_id_foreign foreign key (`lifestyle_question_answer_id`) references `lifestyle_question_answers` (`id`)) 

[PDOException] 
SQLSTATE[42000]: Syntax error or access violation: 1059 Identifier name 'user_lifestyle_question_answers_lifestyle_question_answer_id_foreign' is too long 

Answer 1

您可以通過自定義索引名作爲第二參數放入foreign（）方法中。或者只是使用較短的表/列名稱。

所以，你想要做的事，如：

public function up() 
{ 
    Schema::create('lifestyle_questions', function(Blueprint $table) 
    { 
     $table->increments('id'); 
     $table->string('question'); 
     $table->timestamps(); 
    }); 

    Schema::create('lifestyle_question_answers', function(Blueprint $table) 
    { 
     $table->increments('id'); 
     $table->integer('lifestyle_question_id')->unsigned(); 
     $table->foreign('lifestyle_question_id', 'lq_id_foreign')->references('id')->on('lifestyle_questions'); 
     $table->string('answer'); 
     $table->timestamps(); 
    }); 

    Schema::create('user_lifestyle_question_answers', function(Blueprint $table) 
    { 
     $table->integer('user_id')->unsigned(); 
     $table->foreign('user_id')->references('id')->on('users'); 
     $table->integer('lifestyle_question_answer_id')->unsigned(); 
     $table->foreign('lifestyle_question_answer_id', 'lqa_id_foreign')->references('id')->on('lifestyle_question_answers'); 
    }); 
}