PHP编程：PHP laravel中的多对多关系实例详解

PHP实例
SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for users
-- ----------------------------
DROP TABLE IF EXISTS `users`;
CREATE TABLE `users` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,`name` varchar(255) COLLATE utf8_unicode_ci NOT NULL,`email` varchar(255) COLLATE utf8_unicode_ci NOT NULL,`password` varchar(60) COLLATE utf8_unicode_ci NOT NULL,`remember_token` varchar(100) COLLATE utf8_unicode_ci DEFAULT NULL,`created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',`updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',PRIMARY KEY (`id`),UNIQUE KEY `users_email_unique` (`email`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
-- ----------------------------
-- Records of users
-- ----------------------------
INSERT INTO `users` VALUES ('1','admin','admin@163.com','$2y$10$J/yXqscucanrHAGZp9G6..Tu1Md.SOljX3M8WrHsUdrgat4zeSuhC','ilocXtjZJwhrmIdLG1cKOYegeCwQCkuyx1pYAOLuzY2PpScQFT5Ss7lBCi7i','2016-04-21 16:26:23','2016-12-14 09:29:59');
INSERT INTO `users` VALUES ('2','baidu','10940370@qq.com','$2y$10$2A5zJ4pnJ5uCp1DN3NX.5uj/Ap7P6O4nP2BaA55aFra8/rti1K6I2',null,'2016-04-22 06:48:10','2016-04-22 06:48:10');
INSERT INTO `users` VALUES ('3','fantasy','1009@qq.com','','2017-06-14 10:38:57','2017-06-15 10:39:01');

PHP实例
SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for roles
-- ----------------------------
DROP TABLE IF EXISTS `roles`;
CREATE TABLE `roles` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
-- ----------------------------
-- Records of roles
-- ----------------------------
INSERT INTO `roles` VALUES ('1','超级版主','2016-12-14 09:29:59');
INSERT INTO `roles` VALUES ('2','司令','2016-04-22 06:48:10');
INSERT INTO `roles` VALUES ('3','军长','2017-06-15 10:39:01');
INSERT INTO `roles` VALUES ('4','司长','2017-06-07 10:41:41','2017-06-15 10:41:51');
INSERT INTO `roles` VALUES ('5','团战','2017-06-22 10:41:44','2017-06-28 10:41:54');
INSERT INTO `roles` VALUES ('6','小兵','2017-06-22 10:41:47','2017-06-22 10:41:56');

PHP实例
SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for role_user
-- ----------------------------
DROP TABLE IF EXISTS `role_user`;
CREATE TABLE `role_user` (
 `id` int(10) unsigned NOT NULL AUTO_INCREMENT,`user_id` int(11) DEFAULT NULL,`role_id` int(11) DEFAULT NULL,`created_at` datetime DEFAULT NULL,`updated_at` datetime DEFAULT NULL,PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=latin1;
-- ----------------------------
-- Records of role_user
-- ----------------------------
INSERT INTO `role_user` VALUES ('1','1','2','2017-06-07 11:42:13','2017-06-21 11:32:16');
INSERT INTO `role_user` VALUES ('2','3','2017-06-07 11:32:13','2017-06-07 11:22:13');
INSERT INTO `role_user` VALUES ('3','4','2017-06-07 11:12:13');
INSERT INTO `role_user` VALUES ('4','5','2017-06-07 11:22:13');
INSERT INTO `role_user` VALUES ('5','6','2017-06-07 11:52:13');
INSERT INTO `role_user` VALUES ('6','2017-06-07 11:42:13');
INSERT INTO `role_user` VALUES ('7','2017-06-07 11:52:13');

PHP实例
<?php
namespace AppModels;
use IlluminateDatabaseEloquentModel;
/**
 * Class Role
 * @package AppModels
 * @mixin Eloquent
 */
class Role extends Model
{
}

PHP实例
<?php
namespace AppModels;
use IlluminateDatabaseEloquentModel;
/**
 * Class User
 * @package AppModels
 * @mixin Eloquent
 */
class User extends Model
{
  /**
   * 用户角色
   */
  public function roles()
  {
    return $this->belongsToMany('AppModelsRole');
  }
}

PHP实例
<?php
$user = User::find(1);
$roles = $user->roles;
echo '用户'.$user->name.'所拥有的角色：';
foreach($roles as $role)
  echo $role->name.' '; //对应输出为：用户admin所拥有的角色：司令 军长 团战 

PHP实例
User::find(1)->roles()->orderBy('name')->get();

PHP实例
return $this->belongsToMany('AppModelsRole','user_roles');

PHP实例
return $this->belongsToMany('AppModelsRole','user_roles','user_id','role_id');

PHP实例
<?php
namespace AppModels;
use IlluminateDatabaseEloquentModel;
/**
 * Class Role
 * @package AppModels
 * @mixin Eloquent
 */
class Role extends Model
{
  /**
   * 角色用户
   */
  public function users()
  {
    return $this->belongsToMany('AppModelsUser');
  }
}

PHP实例
$role = Role::find(2);
$users = $role->users;
echo '角色#'.$role->name.'下面的用户：';
foreach ($users as $user) 
　　echo $user->name.' ';//对应输出为：角色#司令下面的用户：admin fantasy baidu

PHP实例
$roles = User::find(1)->roles;
foreach ($roles as $role) 
  echo $role->pivot->role_id.'<br>';//对应输出为:2 3 5

PHP实例
return $this->belongsToMany('AppModelsRole')->withPivot('column1','column2');

PHP实例
<?php
namespace AppModels;
use IlluminateDatabaseEloquentModel;
/**
 * Class User
 * @package AppModels
 * @mixin Eloquent
 */
class User extends Model
{
  /**
   * 用户角色
   */
  public function roles()
  {
    //return $this->belongsToMany('AppModelsRole');
    return $this->belongsToMany('AppModelsRole')->withPivot('username');
  }
}

PHP实例
$user = User::find(1);
foreach ($user->roles as $role) 
　　echo $role->pivot->username;//对应输出为：马特马特2马特3

PHP实例
return $this->belongsToMany('AppModelsRole')->withTimestamps();

PHP实例
return $this->belongsToMany('AppModelsRole')->withPivot('username')->wherePivot('username','马特2');
//return $this->belongsToMany('AppModelsRole')->wherePivotIn('role_id',[1,2]);

PHP实例
$user = User::find(1);
print_r($user->roles->toArray());

PHP实例
Array
(
  [0] => Array
    (
      [id] => 3
      [name] => 军长
      [created_at] => 2017-06-14 10:38:57
      [updated_at] => 2017-06-15 10:39:01
      [pivot] => Array
        (
          [user_id] => 1
          [role_id] => 3
          [username] => 马特2
        )
    )
)

PHP实例
return $this->belongsToMany('AppModelsRole')->withTimestamps();