laravel ORM 一對一 一對多 多對多 原生的MYSQL怎么寫?

問題描述

laravel ORM 一對一、一對多、多對多、原生的MYSQL怎么寫?laravel ORM 的with原理是什么？如題

問題解答

class User extends Model{public function Roles() {return $this->hasOne('AppRole', ’user_id’, ’id’); }}class Message extends Model{public function User() {return $this->belongsTo('AppUser', ’user_id’, ’id’); }}//Controller 輸出sql看DB::listen(function($sql,$binds){ dump($sql,$binds);});$role = User::find(1)->Roles;//一對多類似//select * from `users` where `id` = 1 limit 1 ;//select * from `roles` where `user_id` = 1 limit 1 ; $mess = Message::with(’User’)->where(’type’,$type)->get();//select *from messages where type=?; 查詢出用戶id列表//select * from `users` where `id` in (?);根據id列表查詢用戶信息