是否有寫冗長的where子句

Question

這裏是代碼

DECLARE @List TABLE (n nvarchar(50)); 

INSERT INTO @list (n) VALUES ('A'),('B'),('C'),('D'),('E'); 

SELECT 
    (t1.n) 
    + (t2.n) 
    + (t3.n) 
    + (t4.n) 
    +(t5.n) 
FROM @list AS t1 
JOIN @list AS t2 
    ON 1=1 
JOIN @list AS t3 
    ON 1=1 
JOIN @list AS t4 
    ON 1=1 
JOIN @list AS t5 
    ON 1=1 
WHERE 
    not t1.n = t2.n 
    and not t1.n = t3.n 
    and not t1.n = t4.n 
    and not t1.n = t5.n 
    and not t2.n = t3.n 
    and not t2.n = t4.n 
    and not t2.n = t5.n 
    and not t3.n = t4.n 
    and not t3.n = t5.n 
    and not t4.n = t5.n 

我需要簡化任何短期和簡單的方式where子句像（其中T1.n，T2.n，T3.n ,. T4.n，T5.n不equl對方）

在此先感謝

Answer 1

要創建組合（或者是置換？），你可以使用一個CTE。

如：

;with cte as 
(
select n from @list 
union all 
select convert(nvarchar(50),L.n+ cte.n) from @List L 
    inner join cte on charindex(l.n,cte.n)=0 
where LEN(l.n)<5 

) 
    select * from cte where LEN(n)=5 

Answer 2

可以使用，

NOT IN (....)條款

一樣，

where t1.n NOT IN (t2.n, t3.n, t4.n, t5.n) 
and t2.n NOT IN (t3.n , t4.n,t5.n) 
and t3.n NOT IN (t4.n,t5.n) 

Answer 3

你可以檢查你有多少個不同的值有：

where (
    select count(distinct n) 
    from (values (t1.n), (t2.n), (t3.n), (t4.n), (t5.n)) as ns (n) 
) = 5 

如果您有少於5個不同的值，有些值相等。

SQL Fiddle