模式构建器laravel迁移在两列中是唯一的

如何在两列上设置唯一约束？

class MyModel extends Migration {
  public function up()
  {
    Schema::create('storage_trackers', function(Blueprint $table) {
      $table->increments('id');
      $table->string('mytext');
      $table->unsignedInteger('user_id');
      $table->engine = 'InnoDB';
      $table->unique('mytext', 'user_id');
    });
  }
}

MyMode::create(array('mytext' => 'test', 'user_id' => 1);
// this fails??
MyMode::create(array('mytext' => 'test', 'user_id' => 2);

第二个参数是手动设置唯一索引的名称。使用数组作为第一个参数来创建跨多个列的唯一键。

$table->unique(array('mytext', 'user_id'));

或（稍微整洁）

$table->unique(['mytext', 'user_id']);

只需使用即可

$table->primary(['first', 'second']);

参考：http：//laravel.com/docs/master/migrations#creating-indexes

举个例子：

    Schema::create('posts_tags', function (Blueprint $table) {

        $table->integer('post_id')->unsigned();
        $table->integer('tag_id')->unsigned();

        $table->foreign('post_id')->references('id')->on('posts');
        $table->foreign('tag_id')->references('id')->on('tags');

        $table->timestamps();
        $table->softDeletes();

        $table->primary(['post_id', 'tag_id']);
    });

DB::statement("ALTER TABLE `project_majr_actvities`
               ADD UNIQUE `unique_index`(`activity_sr_no`, `project_id`)");