查找與條件上相同的表值的組合在SQL服務器

Question

我有一個名爲PlayerScore包含玩家的名字和他們的平均成績表：

Id Name  Average 
1 Sakib  80 
2 Tamim  70 
3 Mushfiq 60 
4 Sabbir  50 
5 Ashraful 20 
6 Aftab  40 
7 Rubel  30 
8 Kalu  10 

我想基於一個條件，找到自己的合作伙伴關係的組合， ， 在線播放其平均分值大於40不能與球員，其分值低於40 我嘗試下面的查詢合作伙伴：

select a.Name,a.Average,b.Name,b.Average from ((select * from PlayerScore where Average<=40) as a inner join (select * from PlayerScore where Average<=40) as b on a.Id < b.Id) 

union 

select a.Name,a.Average,b.Name,b.Average from ((select * from PlayerScore where Average>=40) as a inner join (select * from PlayerScore where Average>=40) as b on a.Id < b.Id) 

導致：

Name Average Name Average 
Aftab 40  Kalu 10 
Aftab 40  Rubel 30 
Ashraful 20  Aftab 40 
Ashraful 20  Kalu 10 
Ashraful 20  Rubel 30 
Mushfiq 60  Aftab 40 
Mushfiq 60  Sabbir 50 
Rubel 30  Kalu 10 
Sabbir 50  Aftab 40 
Sakib 80  Aftab 40 
Sakib 80  Mushfiq 60 
Sakib 80  Sabbir 50 
Sakib 80  Tamim 70 
Tamim 70  Aftab 40 
Tamim 70  Mushfiq 60 
Tamim 70  Sabbir 50 

是他們不使用UNION

Answer 1

select distinct a.Name,a.Average,b.Name,b.Average 
from PlayerScore a 
join PlayerScore b 
    on a.Id < b.Id 
    and ( a.Average<=40 and b.Average<=40 
      or a.Average>=40 and b.Average>=40 
     ) 

它可能會導致同一exceution計劃的任何解決方案。

Answer 2

也許你可以做這樣的事情：

SELECT 
    t.*, 
    t2.* 
FROM 
    PlayerScore AS t 
    CROSS JOIN PlayerScore AS t2 
WHERE t.Average>=40 AND t2.Average<40 
ORDER BY t.Name 

Answer 3

您可以根據您的病情2組，給他們不同的值，然後做一個聯接基於價值。像這樣的東西。

;WITH PlayerScore as 
(
SELECT 1 AS Id,'Sakib' AS Name,80 AS Average 
UNION ALL SELECT 2,'Tamim',70 
UNION ALL SELECT 3,'Mushfiq',60 
UNION ALL SELECT 4,'Sabbir',50 
UNION ALL SELECT 5,'Ashraful',20 
UNION ALL SELECT 6,'Aftab',40 
UNION ALL SELECT 7,'Rubel',30 
UNION ALL SELECT 8,'Kalu',10 
),PlayerCriteria AS 
(
SELECT *,CASE WHEN Average >= 40 THEN 1 ELSE 0 END joincondition 
FROM PlayerScore 
) 

SELECT * FROM PlayerCriteria C1 
INNER JOIN PlayerCriteria C2 ON C1.joincondition = C2.joincondition 
AND C1.Id > C2.Id