Sub-queries ActiveRecord Yii

问题:

Is it possible to make sub-queries in ActiveRecord in Yii?

i have a query like this:

select * from table1 where table1.field1 in (select table2.field2 from table2)

i'm currently using the fallowing code:

object1::model()->findAll(array('condition'=>'t.field1 in (select table2.field2 from table2)'))

[Edit]
i would like to know if there is a manner to construct the sub-query without using SQL, and without using joins.

Is there any solution ?

and thanks in advance.

回答1:

First find doublets by db fields:

$model=new MyModel('search');
$model->unsetAttributes();

$criteria=new CDbCriteria();
$criteria->select='col1,col2,col3';
$criteria->group = 'col1,col2,col3';
$criteria->having = 'COUNT(col1) > 1 AND COUNT(col2) > 1 AND COUNT(col3) > 1';

Get the subquery:

$subQuery=$model->getCommandBuilder()->createFindCommand($model->getTableSchema(),$criteria)->getText();

Add the subquery condition:

$mainCriteria=new CDbCriteria();
$mainCriteria->condition=' (col1,col2,col3) in ('.$subQuery.') ';
$mainCriteria->order = 'col1,col2,col3';

How to use:

$result = MyModel::model()->findAll($mainCriteria);

Or:

$dataProvider = new CActiveDataProvider('MyModel', array(
        'criteria'=>$mainCriteria,
));

Source: http://www.yiiframework.com/wiki/364/using-sub-query-for-doubletts/

回答2:

No, there is not a way to programmatically construct a subquery using Yii's CDbCriteria and CActiveRecord. It doesn't look like the Query Builder has a way, either.

You can still do subqueries a few different ways, however:

$results = Object1::model()->findAll(array(
  'condition'=>'t.field1 in (select table2.field2 from table2)')
);

You can also do a join (which will probably be faster, sub-queries can be slow):

$results = Object1::model()->findAll(array(
  'join'=>'JOIN table2 ON t.field1 = table2.field2'
);

You can also do a direct SQL query with findAllBySql:

$results = Object1::model()->findAllBySql('
  select * from table1 where table1.field1 in 
  (select table2.field2 from table2)'
);

You can, however, at least provide a nice AR style interface to these like so:

class MyModel extends CActiveRecord {
  public function getResults() {
    return Object1::model()->findAll(array(
      'condition'=>'t.field1 in (select table2.field2 from table2)')
    );
  }
}

Called like so:

$model = new MyModel();
$results = $model->results;

One interesting alternative idea would be to create your subquery using the Query Builder's CDbCommand or something, and then just pass the resulting SQL query string into a CDbCritera addInCondition()? Not sure if this will work, but it might:

$sql = Yii::app()->db->createCommand()
  ->select('*')
  ->from('tbl_user')
  ->text;
$criteria->addInCondition('columnName',$sql);

You can always extend the base CDbCriteria class to process and build subqueries somehow as well. Might make a nice extension you could release! :)

I hope that helps!

回答3:

I know this an old thread but maybe someone (like me) still needs an answer.

There is a small issues related to the previous answers. So, here is my enhancement:

$model=new SomeModel();
$criteria=new CDbCriteria();
$criteria->compare('attribute', $value);
$criteria->addCondition($condition);
// ... etc
$subQuery=$model->getCommandBuilder()->createFindCommand($model->getTableSchema(),$criteria)->getText();

$mainCriteria=new CDbCriteria();
$mainCriteria->addCondition($anotherCondition);
// ... etc

// NOW THIS IS IMPORTANT 
$mainCriteria->params = array_merge($criteria->params, $mainCriteria->params);

// Now You can pass the criteria:
$result = OtherModel::model()->findAll($mainCriteria);