測試一下你的T-SQL基礎知識-subquery

一直覺得本身SQL挺好的，沒有想到今天在重構存儲過程遇到了一個子查詢的問題，修改成自鏈接以後發現竟然結果不對,因而有了下面的測試。假設表中有以下數數據，請問Query1,Query2,Query3的查詢結果？

ID	OrderID	TransID	Type
1	1	1	E
2	1	1	A
3	1	1	B
4	1	2	A
5	1	2	B
6	2	1	A
7	2	1	B
8	2	2	A

 

--Query 1
SELECT * FROM OrderDetail a
left join OrderDetail b ON a.OrderID=b.OrderID and a.TransID=b.TransID and b.Goods='E'
WHERE b.Goods is  null

--Query 2
SELECT * FROM OrderDetail a
WHERE a.TransID <>
(
   SELECT top 1 b.TransID FROM OrderDetail b WHERE b.OrderID=a.OrderID and b.Goods='E'
)

--Query 3
SELECT * FROM OrderDetail a
WHERE NOT EXISTS 
(
    SELECT  b.TransID,b.orderid  FROM OrderDetail b WHERE b.OrderID=a.OrderID and b.Goods='E'
)

在查看運行結果前請默默的寫下您的答案：
Query1

ID    OrderID    TransID    Goods
4    1    2    A
5    1    2    B
6    2    1    A
7    2    1    B
8    2    2    A

View Code

Query2

ID    OrderID    TransID    Goods
4    1    2    A
5    1    2    B

View Code

Query3

ID    OrderID    TransID    Goods
6    2    1    A
7    2    1    B
8    2    2    A

View Code