单选题

有两张数据表存在于SQLServer中定义如下： CREATE TABL...

Question

有两张数据表存在于SQLServer中定义如下：

CREATE TABLE [dbo].[Customers](
 [customerid] [char](5) NOT NULL PRIMARY KEY ,
 [city] [varchar](10) NOT NULL,
)
CREATE TABLE [dbo].[Orders](
 [orderid] [int] NOT NULL PRIMARY KEY,
 [customerid] [char](5) NULL references
Customers(customerid),
)

以下的SQL-查询来自上海且订单少于3个的客户以及他们的订单数，查询结果按订单数从小到大的顺序排列

① select c.customerid,count(o.orderid)as numorders

② from [Customers] as C  left outer join [Orders] as O on C.customerid=O.customerid

③ where C.city='Shanghai'

④ group by c.customerid

⑤ having count(O.orderid)<3

⑥ order by numorders

该SQL逻辑查询处理顺序应该是

A. ②①③④⑤⑥

B. ①②③④⑤⑥

C. ②③④⑤①⑥

D. ②③④⑤⑥①