SQL使用多個操作選擇完成的訂單

Question

我有一個帶有子操作的訂單列表。我如何創建完成訂單清單？完成的訂單必須完成所有子操作。

表 「訂單」：

order_no | suboperation | finished 
1  | preparing | 01/01/2009 
1  | scrubbing | 01/05/2009 
1  | painting  | 01/10/2009 
2  | preparing | 02/05/09 
2  | painting  | NULL 
3  | preparing | 03/01/2009 
3  | scrubbing | 03/15/2009 
3  | painting  | 03/10/2009 
4  | bending  | NULL 
4  | crashing  | NULL 
4  | staining  | NULL 
4  | painting  | NULL 

所需的輸出（完成訂單）：

order_no 
1 
3 

Answer 1

你也可以使用count,group by and having。這避免了必須做更高效的表連接。

create table #Orders (
    order_no int, 
    suboperation varchar(30), 
    finished smalldatetime) 

insert into #Orders values (1 , 'preparing' , '01/01/2009') 
insert into #Orders values (1 , 'scrubbing' , '01/05/2009') 
insert into #Orders values (1 , 'painting' , '01/10/2009') 
insert into #Orders values (2 , 'preparing' , '02/05/09') 
insert into #Orders values (2 , 'painting' , NULL) 
insert into #Orders values (3 , 'preparing' , '03/01/2009') 
insert into #Orders values (3 , 'scrubbing' , '03/15/2009') 
insert into #Orders values (3 , 'painting' , '03/10/2009') 
insert into #Orders values (4 , 'bending' , NULL) 
insert into #Orders values (4 , 'crashing' , NULL) 
insert into #Orders values (4 , 'staining' , NULL) 
insert into #Orders values (4 , 'painting' , NULL) 

select 
    order_no, 
    count(1) As NoOfSubtasks --count(1) gives the number of rows in the group 
    count(finished) As NoFinished, --count will not count nulls 
from #Stuff 
group by 
    order_no 
having 
    count(finished) = count(1) --if finished = number of tasks then it's complete 

drop table #Orders 

Answer 2

一個很好的醇」 WHERE NOT EXISTS條款應該在這裏工作：

SELECT DISTINCT o.order_no 
FROM orders o 
WHERE NOT EXISTS (SELECT p.order_no 
        FROM orders p 
        WHERE p.order_no = o.order_no 
        AND p.finished IS NULL) 

Answer 3

SELECT order_no, suboperation, finished 
FROM orders o1 
WHERE NOT EXISTS(
    SELECT 1 
     FROM orders o2 
     WHERE o1.order_no = o2.order_no 
     AND o2 IS NULL) 

Answer 4

我試圖找到一種方法，使用MIN功能，並想出了這個：

選擇order_no

從接單

GROUP BY order_no

HAVING （MIN（ISNULL（finished，0））<> 0）

null可能很煩人...

不是表現，也許，但我更容易理解。