Question

请帮助解决此问题我有一张桌子会议

PersonOne   PersonTwo
Ajay        Bharat
Ajay        Elas
Chetan      Deepak
Deepak      Chetan
Chetan      Deepak
Farooq      Ajay
Anil        Sanjay
Gaganan     Hassan
Hassan      Isqh

输出应为

PersonOne   PersonTwo    
Anil        Sanjay

如果用户只想显示仅参加过一次会议的人员巴拉特在这里只举行了一次会议，但他参加了与ajay的会面，ajay曾多次出席会议。所以Bharat不应该在列表中显示

输出应为

PersonOne   PersonTwo    
Chetan      Deepak
Deepak      Chetan
Chetan      Deepak

如果用户想要仅显示第三次参加会议的人员我已尝试过几乎所有可能的陈述，例如ROW_NUMBER() ,RANK() ,DENSE_RANK() ,NTILE，但结果...... plz需要你的帮助

Answer 1

下面的查询需要一些时间 - 毫无疑问，但绝对会给你预期的结果。

SELECT * FROM tblMeeting WHERE (PersonOne IN
(
    SELECT PersonOne FROM 
    (
        SELECT PersonOne, COUNT(*) AS Expr1 FROM 
        (
            SELECT PersonOne FROM tblMeeting AS tblMeeting_3
            UNION ALL
            SELECT PersonTwo FROM tblMeeting AS tblMeeting_1
        ) AS derivedtbl_1 GROUP BY PersonOne
    ) AS derivedtbl_2 WHERE (Expr1 = 1)

)) 
AND (PersonTwo IN 
(
    SELECT PersonOne FROM 
    (
        SELECT PersonOne, COUNT(*) AS Expr1 FROM
        (
            SELECT PersonOne FROM tblMeeting AS tblMeeting_2
            UNION ALL
            SELECT PersonTwo FROM tblMeeting AS tblMeeting_1
        ) AS derivedtbl_1_1 GROUP BY PersonOne
    ) AS derivedtbl_2_1 WHERE (Expr1 = 1)
))

这是小提琴http://sqlfiddle.com/#!2/51b91/4

P.S：您可以提高查询性能。：）

Answer 2

请尝试以下查询

SELECT Person
INTO #TEMP
FROM
(
   SELECT PersonOne as Person FROM tblMeeting
   UNION ALL 
   SELECT PersonTwo  as Person FROM tblMeeting
) P
GROUP By Person 
Having Count(Person) =1

select * from tblMeeting where 
PersonOne in ( select Person from #TEMP) and
PersonTwo in ( select Person from #TEMP)

使用ROW_NUMBER（）2列

2 个答案: