Yii多个表的一个模型

Question

I have Yii application and two tables with same structure tbl and tbl_history:

Now want to create model so it will select table by parameter I send when calling model. For example:

MyModel::model('tbl')->find();
//and
MyModel::model('tbl_history')->find();

Find related article with solution in Yii forum. Made same changes and finally got this in MyModel:

private $tableName = 'tbl'; // <=default value
private static $_models=array();
private $_md;

public static function model($tableName = false, $className=__CLASS__)
{
    if($tableName === null) $className=null; // this string will save internal CActiveRecord functionality
    if(!$tableName)
        return parent::model($className);

    if(isset(self::$_models[$tableName.$className]))
        return self::$_models[$tableName.$className];
    else
    {
      $model=self::$_models[$tableName.$className]=new $className(null);
      $model->tableName = $tableName;

      $model->_md=new CActiveRecordMetaData($model);
      $model->attachBehaviors($model->behaviors());
      return $model;
    }
 }

Now when I make:

echo MyModel::model('tbl_history')->tableName(); // Output: tbl_history

It returns right value, but:

MyModel::model('tbl_history')->find();

still returns value for tbl.

Added:

public function __construct($id=null,$scenario=null){
    var_dump($id);
    echo '<br/>';
    parent::__construct($scenario);
}

and got:

string(tbl_history)
string(tbl_history)
NULL

It means Yii makes call to model from other place but don't know from where and how to prevent it.

Also It makes 2 calls to model, is it too bad for performance?

Answer 1

It looks like the CActiveRecord::getMetaData() method needs to be overridden to achieve what you are looking for.

<?php
class TestActiveRecord extends CActiveRecord
{
    private $tableName = 'tbl'; // <=default value
    private static $_models=array();
    private $_md;

    public function __construct($scenario='insert', $tableName = null)
    {

        if($this->tableName === 'tbl' && $tableName !== null)
            $this->tableName = $tableName;
        parent::__construct($scenario);
    }

    public static function model($tableName = false, $className=__CLASS__)
    {
        if($tableName === null) $className=null; // this string will save internal CActiveRecord functionality
        if(!$tableName)
            return parent::model($className);

        if(isset(self::$_models[$tableName.$className]))
            return self::$_models[$tableName.$className];
        else
        {
            $model=self::$_models[$tableName.$className]=new $className(null);
            $model->tableName = $tableName;

            $model->_md=new CActiveRecordMetaData($model);
            $model->attachBehaviors($model->behaviors());

            return $model;
        }
    }

    public function tableName()
    {
        return $this->tableName;
    }

    /**
     * Returns the meta-data for this AR
     * @return CActiveRecordMetaData the meta for this AR class.
     */
    public function getMetaData()
    {
        if($this->_md!==null)
            return $this->_md;
        else
            return $this->_md=static::model($this->tableName())->_md;
    }

    public function refreshMetaData()
    {
        $finder=static::model($this->tableName());
        $finder->_md=new CActiveRecordMetaData($finder);
        if($this!==$finder)
            $this->_md=$finder->_md;
    }

}