Comparison of methods to find specified fields using find findAll in Yii framework

As we all know

modelName::model() -> find()　 //What is found is an object
modelName::model() -> findALL()　 //What is found It is an array of object collections
How to find the data of the fields I need, not the data of all fields

I did this before

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

Backstage I accidentally saw someone else writing something like this, and realized how ignorant I was

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

After testing, I found that it really works, so find can also operate like this

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

Of course, it is definitely not safe to do this. It can be replaced by the following method.

$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'),
));

Similarly, it can also be tested with findAll. Conclusion

This method can easily obtain the required data. Of course, when paging is required, new is required for the following CDbCriteria.

For example, I want to take out the 'v_id', 'title' in the videoinfo table, 'big_class', 'sub_class', 'upload_time', 'comment_num' and other fields, and the condition is status=1, follow lastmodifytime in reverse order, and only take out 3, do this:

$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);

The line I commented out can be used to pass variables, represented by placeholders. For example, if your status needs to be conditionally assigned according to variables, you can assign a value in the commented line, and then write ## in the condition condition. #

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

That’s it,

In this way, the $result variable is the result you obtained. It is a list of objects and needs to be traversed:

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

For example, if you want to display each field, just type

$ob->attributes['title'];

and so on.

is finished. The CPagination class can be used together with the CDbCriteria class and the front-end paging plug-in. Support paging:

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

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

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