Php Yii Mysql选择自定义字段

我希望在一个字段中有两个自定义字段。 我该怎么做

---

代码：

表:

number   custom_field
------------------
2         4, 8
3         6, 12

custom_field ordered -> 4, 6, 8, 12

---

编辑：

第一。Events.php

class Events extends CActiveRecord {
    public $custom_square, $custome_square_square;
// skip ...
    public funciton rules() {
    // skip ...
          array('custom_square, custom_square_square', 'safe'),

第二。单独的sql选择：

$criteria->select = array(
    new CDbExpression('(number*2) AS custom_square'), 
    new CDbExpression('(number*4) AS custom_square_square'),
);
$criteria->order='custom_square';
$model = Events::model()->findAll($criteria);

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谢谢你再次帮助我！请检查原始帖子中的编辑，我如何在同一

TbGridView

顺序中列出2个不同的字段？

Custom Field
4
6
8
12

class Events extends CActiveRecord {
    public $custom_square, $custome_square_square;
// skip ...
    public funciton rules() {
    // skip ...
          array('custom_square, custom_square_square', 'safe'),

$criteria->select = array(
    new CDbExpression('(number*2) AS custom_square'), 
    new CDbExpression('(number*4) AS custom_square_square'),
);
$criteria->order='custom_square';
$model = Events::model()->findAll($criteria);