CJoinQuery

public function __construct($joinElement,$criteria=null)
{
    if($criteria!==null)
    {
        $this->selects[]=$joinElement->getColumnSelect($criteria->select);
        $this->joins[]=$joinElement->getTableNameWithAlias();
        $this->joins[]=$criteria->join;
        $this->conditions[]=$criteria->condition;
        $this->orders[]=$criteria->order;
        $this->groups[]=$criteria->group;
        $this->havings[]=$criteria->having;
        $this->limit=$criteria->limit;
        $this->offset=$criteria->offset;
        $this->params=$criteria->params;
        if(!$this->distinct && $criteria->distinct)
            $this->distinct=true;
    }
    else
    {
        $this->selects[]=$joinElement->getPrimaryKeySelect();
        $this->joins[]=$joinElement->getTableNameWithAlias();
        $this->conditions[]=$joinElement->getPrimaryKeyRange();
    }
    $this->elements[$joinElement->id]=true;
}

public function createCommand($builder)
{
    $sql=($this->distinct ? 'SELECT DISTINCT ':'SELECT ') . implode(', ',$this->selects);
    $sql.=' FROM ' . implode(' ',$this->joins);

    $conditions=array();
    foreach($this->conditions as $condition)
        if($condition!=='')
            $conditions[]=$condition;
    if($conditions!==array())
        $sql.=' WHERE (' . implode(') AND (',$conditions).')';

    $groups=array();
    foreach($this->groups as $group)
        if($group!=='')
            $groups[]=$group;
    if($groups!==array())
        $sql.=' GROUP BY ' . implode(', ',$groups);

    $havings=array();
    foreach($this->havings as $having)
        if($having!=='')
            $havings[]=$having;
    if($havings!==array())
        $sql.=' HAVING (' . implode(') AND (',$havings).')';

    $orders=array();
    foreach($this->orders as $order)
        if($order!=='')
            $orders[]=$order;
    if($orders!==array())
        $sql.=' ORDER BY ' . implode(', ',$orders);

    $sql=$builder->applyLimit($sql,$this->limit,$this->offset);
    $command=$builder->getDbConnection()->createCommand($sql);
    $builder->bindValues($command,$this->params);
    return $command;
}

public function join($element)
{
    if($element->slave!==null)
        $this->join($element->slave);
    if(!empty($element->relation->select))
        $this->selects[]=$element->getColumnSelect($element->relation->select);
    $this->conditions[]=$element->relation->condition;
    $this->orders[]=$element->relation->order;
    $this->joins[]=$element->getJoinCondition();
    $this->joins[]=$element->relation->join;
    $this->groups[]=$element->relation->group;
    $this->havings[]=$element->relation->having;

    if(is_array($element->relation->params))
    {
        if(is_array($this->params))
            $this->params=array_merge($this->params,$element->relation->params);
        else
            $this->params=$element->relation->params;
    }
    $this->elements[$element->id]=true;
}