Yii框架中 find findAll 查找出制定的字段的方法对比
author:一佰互联 2019-04-28   click:154

众所周知

modelName::model() -> find()    //找出的是一个对象
modelName::model() -> findALL()  //找出的是一个对象集合的数组
如何找出我所需要的字段的数据,而不是全部字段的数据

之前我是这么做的

$criteria = new CDbCriteria;
$criteria->select = "username,id,email";
$criteria->order = "id DESC";
$users = modelName::model()->findAll( $criteria );

后台无意中看到别人有这么写的,发现自己是多么的无知

$users = modelName::model()->findAll(array(
  "select" =>array("username","id","email"),
  "order" => "id DESC", 
));

测试后发现果然可以用,那么find也可以这么操作

$user = modelName::model()->find(array(
  "select" =>array("username","id","email"),
  "order" => "id DESC",
  "condition" => "id=".$id,
));

当然了,这么做肯定不安全了,换成下面的方法同样可以

$users = $this->user->find(array(
  "select"=>array("id","username","email"),
  "order" => "id DESC",
  "condition" => "state=:state AND id=:id",
  "params" => array(":state"=>"1",":id" => "2"),
));

同理用findAll测试了也可以,结论

通过这种方法能够很方便的获取所需要的数据,当然需要分页的时候还是 需要 new 以下 CDbCriteria 的

比如我要取出videoinfo表中的"v_id","title","big_class","sub_class","upload_time","comment_num" 等字段,且条件是status=1的,按照lastmodifytime倒序,且只取出3条即可,这样操作:

$criteria = new CDbCriteria() ; 
$criteria -> select = array("v_id","title","big_class","sub_class","upload_time","comment_num");     
$criteria -> condition = "status = 1"; 
$criteria -> order = "lastmodifytime desc"; 
$criteria -> limit = 3; 
 $criteria ->params = array (":status" => $你的变量) ; 
$result = VideoInfo::model()->findAll($criteria); 

其中我注释掉的那一行是可以传变量的,用占位符表示,比如你的status需要按照变量来条件赋值的话,可以在注释的那行赋值,然后在condition条件写成

$criteria -> condition = "status = :status"; 

即可,
这样,$result变量时你取得的结果,它是个对象列表,需要遍历一下:

foreach ($result as $ob){ 
      print_r($ob->attributes); 
 } 

比如你想展示每个字段只需打出

$ob->attributes["title"]; 

等等即可

领完,CPagination类可以和CDbCriteria类以及前台的分页插件一起用来支持分页:

      $count =VideoInfo::model()->count($criteria)

      $pages=new CPagination($count);    
      $pages->pageSize=30; //每页分多少条
      $pages->applyLimit($criteria); 

$result = VideoInfo::model()->findAll($criteria);