我使用createCommand并运行下面的查询，但在我的项目中出现错误
$all_project_tasks = Yii::app()->db->createCommand("
set @prevOrder=0;
set @mm=0;
set@dt=0;
select * from project_task_user_id ptui right join
(select id,`desc`,due_time,list_id,if(@prevOrder=`order`,
@dt,@dt:=@dt+due_time) this_finish_due,if(@prevOrder=`order`,
@mm,if(@prevOrder=0,@mm,@mm:=@dt-due_time)) prev_due,@prevOrder:=`order` as `order`
from (select id,`desc`,due_time,`order`,list_id from project_task a
where a.list_id in (select id from project_list where project_id=1 )
and (a.due_time is not null) order by a.order asc,a.due_time desc ) as b) l
ON ptui.project_task = l.id where ptui.member_id =7 ")
->queryAll();
并得到这个错误
SQLSTATE[HY000]：一般错误。执行的SQL语句是
为什么会出现此错误？我哪里错了？creatCommand不支持sql中的@variable？
Yii的createCommand是基于PDO的，因此不支持多查询执行。
$all_project_tasks = Yii::app()->db->createCommand("set @prevOrder=0")->execute();
$all_project_tasks = Yii::app()->db->createCommand("set @mm=0")->execute();
$all_project_tasks = Yii::app()->db->createCommand("set @dt=0")->execute();
$all_project_tasks = Yii::app()->db->createCommand('select * from project_task_user_id ptui right join (select id,`desc`,due_time,list_id,if(@prevOrder=`order`,@dt,@dt:=@dt+due_time) this_finish_due,if(@prevOrder=`order`,@mm,if(@prevOrder=0,@mm,@mm:=@dt-due_time)) prev_due,@prevOrder:=`order` as `order`
from (select id,`desc`,due_time,`order`,list_id from project_task a where a.list_id in (select id from project_list where project_id=1 )and (a.due_time is not null) order by a.order asc,a.due_time desc ) as b) l
ON ptui.project_task = l.id where ptui.member_id =7')->queryAll();
我认为这一定行得通。