public function search()
{
  // Warning: Please modify the following code to remove attributes that
  // should not be searched.
  $criteria=new CDbCriteria;
  $criteria->compare('id',$this->id);
  $criteria->compare('title',$this->title,true); //支持模糊查找
  $criteria->compare('content',$this->content,true); //支持模糊查找
  $criteria->compare('type',$this->type);
  $criteria->compare('user',$this->user,true); //支持模糊查找
  $criteria->compare('status',$this->status);
  $criteria->compare('create_data',$this->create_data,true); //支持模糊查找
  return new CActiveDataProvider($this, array(
    'criteria'=>$criteria,
    'pagination'=>array(
      'pageSize'=>50,
    ),
  ));
}

$criteria->compare('create_time','<='.$this->endtime),
//创建早间小于等于指定时间

//查找的结果
$criteria->select = 'id,title,content,author,status,createtime',
//也可以以下一种方式定义
$criteria->select = array('id','title','content','author','status','createtime'),

//定义条件
$criteria->select = 'status=1',
//添加匹配
$criteria->compare('title',$this->title,true),
//添加条件 $condition可以是数组，也可以是字符串，and可以省略
$criteria->addCondition($condition,'and'),
//添加IN条件 $column为字段名
$criteria->addInCondition(string $column, array $values, string $operator='AND')
//添加notin条件
$criteria->addNotInCondition(string $column, array $values, string $operator='AND')
//添加like条件
$criteria->addSearchCondition(string $column, string $keyword),
//添加Between条件
$criteria->addBetweenCondition(string $column, string $valueStart, string $valueEnd, string $operator='AND')，

$criteria->join = 'LEFT JOIN users ON users.id=authorID',

$criteria->order = 'createtime DESC',

$criteria->group = 'projectID, teamID',

$criteria->having = 'SUM(revenue)<50000',