二階meged查詢

Question

我有Customers表，我想拔出最短和最長的客戶名稱

我不喜歡這樣寫道：

(SELECT TOP 1 CustomerName, LEN(CustomerName) AS LENGTH FROM Customers ORDER BY LEN(CustomerName) ASC, CustomerName ASC) 
UNION 
(SELECT TOP 1 CustomerName, LEN(CustomerName) AS LENGTH FROM Customers ORDER BY LEN(CustomerName) DESC, CustomerName ASC) 

我得到兩個正確的結果，但現在我想整理他們通過LENGTH列。我已經試過這樣：

SELECT * FROM 
(
(SELECT TOP 1 CustomerName, LEN(CustomerName) AS LENGTH FROM Customers ORDER BY LEN(CustomerName) ASC, CustomerName ASC) 
UNION 
(SELECT TOP 1 CustomerName, LEN(CustomerName) AS LENGTH FROM Customers ORDER BY LEN(CustomerName) DESC, CustomerName ASC) 
) 
ORDER BY LEN(CustomerName) ASC 

但它給我這個錯誤：Syntax error in JOIN operation.

我怎麼能這樣做？

Answer 1

select customername,len(customername) as namelength 
from (SELECT MAX(LEN(CustomerName)) AS MAXLENGTH, MIN(LEN(CustomerName)) AS MINLENGTH 
     FROM Customers) lens 
join customers c on c.len(customername) = lens.maxlength or c.len(customername) = lens.minlength 
order by namelength desc, customername