发布于 2017-08-27 09:55:19 | 29 次阅读 | 评论: 0 | 来源: 网友投递

这里有新鲜出炉的YII 2.0教程,程序狗速度看过来!

Yii高性能PHP框架

Yii Framework是一个基于组件、用于开发大型 Web 应用的高性能 PHP 框架。Yii提供了今日Web 2.0应用开发所需要的几乎一切功能。Yii是最有效率的PHP框架之一。Yii是创始人薛强的心血结晶,于2008年1月1日开始开发。


这篇文章主要为大家详细介绍了Yii多表联查操作,对Yii多表联合查询操作进行了总结,感兴趣的小伙伴们可以参考一下

本文针对Yii多表联查进行汇总描述,供大家参考,具体内容如下

1、多表联查实现方法

有两种方式一种使用DAO写SQL语句实现,这种实现理解起来相对轻松,只要保证SQL语句不写错就行了。缺点也很明显,比较零散,而且不符合YII的推荐框架,最重要的缺点在于容易写错。

还有一种便是下面要说的使用YII自带的CActiveRecord实现多表联查

2、 整体框架

我们需要找到一个用户的好友关系,用户的信息放在用户表中,用户之间的关系放在关系表中,而关系的内容则放在关系类型表中。明显的我们只需要以关系表为主表联查其他两个表即可。我主要从代码的角度,分析下实现的过程。

3、CActiveRecord

我们首先需要对3张表建立相应的model,下面是关系表的代码

SocialRelation.php


<?php 
/** 
 * This is the model class for table "{{social_relation}}". 
 * 
 * The followings are the available columns in table '{{social_relation}}': 
 * @property integer $relation_id 
 * @property integer $relation_type_id 
 * @property integer $user_id 
 * @property integer $another_user_id 
 * 
 * The followings are the available model relations: 
 * @property SocialRelationType $relationType 
 * @property AccessUser $user 
 * @property AccessUser $anotherUser 
 */ 
class SocialRelation extends CActiveRecord 
{ 
  /** 
   * Returns the static model of the specified AR class. 
   * @param string $className active record class name. 
   * @return SocialRelation the static model class 
   */ 
  public static function model($className=__CLASS__) 
  { 
    return parent::model($className); 
  } 
  /** 
   * @return string the associated database table name 
   */ 
  public function tableName() 
  { 
    return '{{social_relation}}'; 
  } 
  /** 
   * @return array validation rules for model attributes. 
   */ 
  public function rules() 
  { 
    // NOTE: you should only define rules for those attributes that 
    // will receive user inputs. 
    return array( 
      array('relation_type_id, user_id, another_user_id', 'numerical', 'integerOnly'=>true), 
      // The following rule is used by search(). 
      // Please remove those attributes that should not be searched. 
      array('relation_id, relation_type_id, user_id, another_user_id', 'safe', 'on'=>'search'), 
    ); 
  } 
  /** 
   * @return array relational rules. 
   */ 
  public function relations() 
  { 
    // NOTE: you may need to adjust the relation name and the related 
    // class name for the relations automatically generated below. 
    return array( 
      'relationType' => array(self::BELONGS_TO, 'SocialRelationType', 'relation_type_id'), 
      'user' => array(self::BELONGS_TO, 'AccessUser', 'user_id'), 
      'anotherUser' => array(self::BELONGS_TO, 'AccessUser', 'another_user_id'), 
    ); 
  } 
  /** 
   * @return array customized attribute labels (name=>label) 
   */ 
  public function attributeLabels() 
  { 
    return array( 
      'relation_id' => 'Relation', 
      'relation_type_id' => 'Relation Type', 
      'relation_type_name' => 'Relation Name', 
      'user_id' => 'User ID', 
      'user_name' => 'User Name', 
      'another_user_id' => 'Another User', 
      'another_user_name' => 'Another User Name', 
    ); 
  } 
  /** 
   * Retrieves a list of models based on the current search/filter conditions. 
   * @return CActiveDataProvider the data provider that can return the models based on the search/filter conditions. 
   */ 
  public function search() 
  { 
    // Warning: Please modify the following code to remove attributes that 
    // should not be searched. 
    $criteria=new CDbCriteria; 
    $criteria->compare('relation_id',$this->relation_id); 
    $criteria->compare('relation_type_id',$this->relation_type_id); 
    $criteria->compare('user_id',$this->user_id); 
    $criteria->compare('another_user_id',$this->another_user_id); 
    $criteria->with=array( 
      'relationType', 
    ); 
    return new CActiveDataProvider($this, array( 
      'criteria'=>$criteria, 
    )); 
  } 
} 

为了描述方便我们约定 主表为A表(执行查询的那个表), 引用表为B表(外键所引用的表)
建议使用Gii自动生成模型,这样能够节省大量胜博發,为了测试方便,可以对主表生成CRUD,就是增删改查页面,其他的引用表只用生成model就行了。
1. model函数、tablename函数用于得到这个模型和得到数据库表基本信息。自动生成无需修改

2.rules函数,这个函数主要用于规定参数检验方式,注意即使有些参数不需要校验,也必须出现在rules中。不然模型将无法得到参数

3.relation函数,这个函数十分关键,用于定义表之间的关系,下面我将详细说明其中含义

'relationType' => array(self::BELONGS_TO, 'SocialRelationType', 'relation_type_id')  
 这句代码中结构如下
'VarName'=>array('RelationType', 'ClassName', 'ForeignKey', ...additional options)
VarName 是关系的名字,我们以后会用这个名字访问外键引用表的字段

RelationType是关系的类型,十分重要,如果设定错误会导致一些奇怪而且难以检查的错误,Yii一共提供了4种关系

BELONGS_TO(属于): 如果表 A 和 B 之间的关系是一对多,则 表 B 属于 表 A
HAS_MANY(有多个): 如果表 A 和 B 之间的关系是一对多,则 A 有多个 B
HAS_ONE(有一个): 这是 HAS_MANY 的一个特例,A 最多有一个 B
MANY_MANY: 这个对应于数据库中的 多对多关系
ClassName是引用表名,就是外键所引用的表的名字,也就是B表表名

ForeignKey是外键名,主要这里填写的是外键在主表中的名字,也就是外键在A表中的表名,切记不要填错了

如果B表中是双主键可以采用下列方式实现,从软件工程的角度不推荐这样的做法,每个表最好使用独立无意义主键,不然容易出现各种问题,而且不方便管理


'categories'=>array(self::MANY_MANY, 'Category', 
        'tbl_post_category(post_id, category_id)'), 

 additional option 附加选项,很少用到
4 attributeLabels函数,这就是表属性的显示名称了,有点点像powerdesigner中code和name的关系前面一部分为数据库字段名,后面一部分为显示名称
5 search函数,用于生成表查询结果的函数,可以在此加一些限制条件,具体的使用方法就不在这里说明了,可以参考API中CDbCriteria的讲解。如果使用Gii生成那么不需要怎么修改。

同理我们生成,剩下的两个引用表

关系类型表:SocialRelationType.php


<?php 
/** 
 * This is the model class for table "{{social_relation_type}}". 
 * 
 * The followings are the available columns in table '{{social_relation_type}}': 
 * @property integer $relation_type_id 
 * @property string $relation_type_name 
 * 
 * The followings are the available model relations: 
 * @property SocialRelation[] $socialRelations 
 */ 
class SocialRelationType extends CActiveRecord 
{ 
  /** 
   * Returns the static model of the specified AR class. 
   * @param string $className active record class name. 
   * @return SocialRelationType the static model class 
   */ 
  public static function model($className=__CLASS__) 
  { 
    return parent::model($className); 
  } 
  /** 
   * @return string the associated database table name 
   */ 
  public function tableName() 
  { 
    return '{{social_relation_type}}'; 
  } 
  /** 
   * @return array validation rules for model attributes. 
   */ 
  public function rules() 
  { 
    // NOTE: you should only define rules for those attributes that 
    // will receive user inputs. 
    return array( 
      array('relation_type_name', 'length', 'max'=>10), 
      // The following rule is used by search(). 
      // Please remove those attributes that should not be searched. 
      array('relation_type_id, relation_type_name', 'safe', 'on'=>'search'), 
    ); 
  } 
  /** 
   * @return array relational rules. 
   */ 
  public function relations() 
  { 
    // NOTE: you may need to adjust the relation name and the related 
    // class name for the relations automatically generated below. 
    return array( 
      'socialRelations' => array(self::HAS_MANY, 'SocialRelation', 'relation_type_id'), 
    ); 
  } 
  /** 
   * @return array customized attribute labels (name=>label) 
   */ 
  public function attributeLabels() 
  { 
    return array( 
      'relation_type_id' => 'Relation Type', 
      'relation_type_name' => 'Relation Type Name', 
    ); 
  } 
  /** 
   * Retrieves a list of models based on the current search/filter conditions. 
   * @return CActiveDataProvider the data provider that can return the models based on the search/filter conditions. 
   */ 
  public function search() 
  { 
    // Warning: Please modify the following code to remove attributes that 
    // should not be searched. 
    $criteria=new CDbCriteria; 
    $criteria->compare('relation_type_id',$this->relation_type_id); 
    $criteria->compare('relation_type_name',$this->relation_type_name,true); 
    return new CActiveDataProvider($this, array( 
      'criteria'=>$criteria, 
    )); 
  } 
} 

用户表:AccessUser.php


<?php 
/** 
 * This is the model class for table "{{access_user}}". 
 * 
 * The followings are the available columns in table '{{access_user}}': 
 * @property integer $id 
 * @property string $name 
 * @property string $password 
 * @property string $lastlogin 
 * @property string $salt 
 * @property string $email 
 * @property integer $status 
 * 
 * The followings are the available model relations: 
 * @property SocialRelation[] $socialRelations 
 * @property SocialRelation[] $socialRelations1 
 */ 
class AccessUser extends CActiveRecord 
{ 
  /** 
   * Returns the static model of the specified AR class. 
   * @param string $className active record class name. 
   * @return AccessUser the static model class 
   */ 
  public static function model($className=__CLASS__) 
  { 
    return parent::model($className); 
  } 
  /** 
   * @return string the associated database table name 
   */ 
  public function tableName() 
  { 
    return '{{access_user}}'; 
  } 
  /** 
   * @return array validation rules for model attributes. 
   */ 
  public function rules() 
  { 
    // NOTE: you should only define rules for those attributes that 
    // will receive user inputs. 
    return array( 
      array('status', 'numerical', 'integerOnly'=>true), 
      array('name, password, salt, email', 'length', 'max'=>255), 
      array('lastlogin', 'safe'), 
      // The following rule is used by search(). 
      // Please remove those attributes that should not be searched. 
      array('id, name, password, lastlogin, salt, email, status', 'safe', 'on'=>'search'), 
    ); 
  } 
  /** 
   * @return array relational rules. 
   */ 
  public function relations() 
  { 
    // NOTE: you may need to adjust the relation name and the related 
    // class name for the relations automatically generated below. 
    return array( 
      'user_name' => array(self::HAS_MANY, 'SocialRelation', 'user_id'), 
      'anotherUser_name' => array(self::HAS_MANY, 'SocialRelation', 'another_user_id'), 
    ); 
  } 
  /** 
   * @return array customized attribute labels (name=>label) 
   */ 
  public function attributeLabels() 
  { 
    return array( 
      'id' => 'ID', 
      'name' => 'Name', 
      'password' => 'Password', 
      'lastlogin' => 'Lastlogin', 
      'salt' => 'Salt', 
      'email' => 'Email', 
      'status' => 'Status', 
    ); 
  } 
  /** 
   * Retrieves a list of models based on the current search/filter conditions. 
   * @return CActiveDataProvider the data provider that can return the models based on the search/filter conditions. 
   */ 
  public function search() 
  { 
    // Warning: Please modify the following code to remove attributes that 
    // should not be searched. 
    $criteria=new CDbCriteria; 
    $criteria->compare('id',$this->id); 
    $criteria->compare('name',$this->name,true); 
    $criteria->compare('password',$this->password,true); 
    $criteria->compare('lastlogin',$this->lastlogin,true); 
    $criteria->compare('salt',$this->salt,true); 
    $criteria->compare('email',$this->email,true); 
    $criteria->compare('status',$this->status); 
    return new CActiveDataProvider($this, array( 
      'criteria'=>$criteria, 
    )); 
  } 
} 

4、Controller
三张表介绍完了后,下面就应当介绍Controller了,同样的我们使用Gii生成主表(A表)的CRUD后就能得到controller,我们只需要对其进行一些修改即可,代码如下

SocialRelationController.php


<?php 
class SocialRelationController extends Controller 
{ 
  /** 
   * @var string the default layout for the views. Defaults to '//layouts/column2', meaning 
   * using two-column layout. See 'protected/views/layouts/column2.php'. 
   */ 
  public $layout='//layouts/column2'; 
  /** 
   * @return array action filters 
   */ 
  public function filters() 
  { 
    return array( 
      'accessControl', // perform access control for CRUD operations 
      'postOnly + delete', // we only allow deletion via POST request 
    ); 
  } 
  /** 
   * Specifies the access control rules. 
   * This method is used by the 'accessControl' filter. 
   * @return array access control rules 
   */ 
  public function accessRules() 
  { 
    return array( 
      array('allow', // allow all users to perform 'index' and 'view' actions 
        'actions'=>array('index','view'), 
        'users'=>array('*'), 
      ), 
      array('allow', // allow authenticated user to perform 'create' and 'update' actions 
        'actions'=>array('create','update'), 
        'users'=>array('@'), 
      ), 
      array('allow', // allow admin user to perform 'admin' and 'delete' actions 
        'actions'=>array('admin','delete'), 
        'users'=>array('admin'), 
      ), 
      array('deny', // deny all users 
        'users'=>array('*'), 
      ), 
    ); 
  } 
  /** 
   * Displays a particular model. 
   * @param integer $id the ID of the model to be displayed 
   */ 
  public function actionView($id) 
  { 
    $this->render('view',array( 
      'model'=>$this->loadModel($id), 
    )); 
  } 
  /** 
   * Creates a new model. 
   * If creation is successful, the browser will be redirected to the 'view' page. 
   */ 
  public function actionCreate() 
  { 
    $model=new SocialRelation; 
    // Uncomment the following line if AJAX validation is needed 
    // $this->performAjaxValidation($model); 
    if(isset($_POST['SocialRelation'])) 
    { 
      $model->attributes=$_POST['SocialRelation']; 
      if($model->save()) 
        $this->redirect(array('view','id'=>$model->relation_id)); 
    } 
    $this->render('create',array( 
      'model'=>$model, 
    )); 
  } 
  /** 
   * Updates a particular model. 
   * If update is successful, the browser will be redirected to the 'view' page. 
   * @param integer $id the ID of the model to be updated 
   */ 
  public function actionUpdate($id) 
  { 
    $model=$this->loadModel($id); 
    // Uncomment the following line if AJAX validation is needed 
    // $this->performAjaxValidation($model); 
    if(isset($_POST['SocialRelation'])) 
    { 
      $model->attributes=$_POST['SocialRelation']; 
      if($model->save()) 
        $this->redirect(array('view','id'=>$model->relation_id)); 
    } 
    $this->render('update',array( 
      'model'=>$model, 
    )); 
  } 
  /** 
   * Deletes a particular model. 
   * If deletion is successful, the browser will be redirected to the 'admin' page. 
   * @param integer $id the ID of the model to be deleted 
   */ 
  public function actionDelete($id) 
  { 
    $this->loadModel($id)->delete(); 
    // if AJAX request (triggered by deletion via admin grid view), we should not redirect the browser 
    if(!isset($_GET['ajax'])) 
      $this->redirect(isset($_POST['returnUrl']) ? $_POST['returnUrl'] : array('admin')); 
  } 
  /** 
   * Lists all models. 
   */ 
  public function actionIndex() 
  { 
    if(Yii::app()->user->id != null){ 
      $dataProvider=new CActiveDataProvider( 
        'SocialRelation',  
        array('criteria'=>array('condition'=>'user_id='.Yii::app()->user->id, 
      )) 
      ); 
      $this->render('index',array( 
        'dataProvider'=>$dataProvider, 
      )); 
    } 
  } 
  /** 
   * Manages all models. 
   */ 
  public function actionAdmin() 
  { 
    $model=new SocialRelation('search'); 
    $model->unsetAttributes(); // clear any default values 
    if(isset($_GET['SocialRelation'])) 
      $model->attributes=$_GET['SocialRelation']; 
    $this->render('admin',array( 
      'model'=>$model, 
    )); 
  } 
  /** 
   * Returns the data model based on the primary key given in the GET variable. 
   * If the data model is not found, an HTTP exception will be raised. 
   * @param integer $id the ID of the model to be loaded 
   * @return SocialRelation the loaded model 
   * @throws CHttpException 
   */ 
  public function loadModel($id) 
  { 
    $model=SocialRelation::model()->findByPk($id); 
    if($model===null) 
      throw new CHttpException(404,'The requested page does not exist.'); 
    return $model; 
  } 
  /** 
   * Performs the AJAX validation. 
   * @param SocialRelation $model the model to be validated 
   */ 
  protected function performAjaxValidation($model) 
  { 
    if(isset($_POST['ajax']) && $_POST['ajax']==='social-relation-form') 
    { 
      echo CActiveForm::validate($model); 
      Yii::app()->end(); 
    } 
  } 
} 

简单介绍下其中各个函数和变量
$layout 就是布局文件的位置了,布局文件如何使用,这里不做讨论

filters 定义过滤器,这里面水很深

accessRules 访问方式,就是那些用户能够访问到这个模块


array('allow', // allow all users to perform 'index' and 'view' actions 
        'actions'=>array('index','view'), 
        'users'=>array('*'), 
      ), 

allow 表示允许访问的规则如下,deny表示拒绝访问的规则如下。
action表示规定规则使用的动作

user表示规则适用的用户群组,*表示所有用户,@表示登录后的用户,admin表示管理员用户

actionXXX 各个action函数

这里值得注意的是 这个函数


public function actionIndex() 
  { 
    if(Yii::app()->user->id != null){ 
      $dataProvider=new CActiveDataProvider( 
        'SocialRelation',  
        array('criteria'=>array('condition'=>'user_id='.Yii::app()->user->id, 
      )) 
      ); 
      $this->render('index',array( 
        'dataProvider'=>$dataProvider, 
      )); 
    } 
  } 

其中我们可以在dataProvider中设置相应的查询条件,注意这里设置是对于主表(A表)进行的,用的字段名也是主表中的,因为我们要显示的是当前用户的好友,于是,这里我们使用Yii::app()->user->id取得当前用户的id 。

loadModel 用于装载模型,这里我们可以看到findByPk查询了数据库。

performAjaxValidation 用于Ajax验证。

5、视图View

index.php


<?php 
/* @var $this SocialRelationController */ 
/* @var $dataProvider CActiveDataProvider */ 
$this->breadcrumbs=array( 
  'Social Relations', 
); 
?> 
<h1>Social Relations</h1> 
<?php $this->widget('zii.widgets.CListView', array( 
  'dataProvider'=>$dataProvider, 
  'itemView'=>'_view', 
)); ?> 

我们使用一个 CListView控件进行显示,其中itemView为内容显示的具体表单,dataProvider这个是内容源,我们在controller中已经设定了。

_view.php


<?php 
/* @var $this SocialRelationController */ 
/* @var $data SocialRelation */ 
?> 
<div class="view"> 
  <b><?php echo CHtml::encode($data->getAttributeLabel('relation_id')); ?>:</b> 
  <?php echo CHtml::link(CHtml::encode($data->relation_id), array('view', 'id'=>$data->relation_id)); ?> 
  <br /> 
  <b><?php echo CHtml::encode($data->getAttributeLabel('relation_type_id')); ?>:</b> 
  <?php echo CHtml::encode($data->relation_type_id); ?> 
  <br /> 
  <b><?php echo CHtml::encode($data->getAttributeLabel('relation_type_name')); ?>:</b> 
  <?php  
    echo $data->relationType->relation_type_name; 
  ?> 
  <br /> 
  <b><?php echo CHtml::encode($data->getAttributeLabel('user_id')); ?>:</b> 
  <?php echo CHtml::encode($data->user_id); ?> 
  <br /> 
  <b><?php echo CHtml::encode($data->getAttributeLabel('user_name')); ?>:</b> 
  <?php  
    echo $data->user->name; 
  ?> 
  <br /> 
  <b><?php echo CHtml::encode($data->getAttributeLabel('another_user_id')); ?>:</b> 
  <?php echo CHtml::encode($data->another_user_id); ?> 
  <br /> 
  <b><?php echo CHtml::encode($data->getAttributeLabel('another_user_name')); ?>:</b> 
  <?php 
    echo $data->anotherUser->name; 
  ?> 
  <br /> 
</div> 

主要都是类似的,我们看其中的一条

<b><?php echo CHtml::encode($data->getAttributeLabel('relation_type_name')); ?>:</b>  
<?php echo $data->relationType->relation_type_name; ?>
 
第一行为显示标签,在模型中我们设定的显示名就在这里体现出来
第二行为内容显示,这里的relationType是在模型中设置的关系名字,后面的relation_type_name是引用表的字段名(B表中的名字)

6、总结

通过上面的步骤,我们就实现了整个联合查询功能,效果图如下所示:

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持PHPERZ。



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