條件行以單行的MySQL

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event    | time      |id   | user 
    --------------------------------------------------------------------- 
    ADDMEMBER   | 2017-06-14 08:03:58.872908 | 2335797 | x  
    REMOVEMEMBER  | 2017-06-14 09:17:02.719318 | 2337422 | x 
    ADDMEMBER   | 2017-06-14 09:28:23.343281 | 2337737 | x 
    REMOVEMEMBER  | 2017-06-14 09:46:50.189582 | 2338117 | x

我所需的輸出是每個使用addMember組和REMOVEMBER 1行：

event    | Login      | Logoff      |user 
    --------------------------------------------------------------------------------------- 
    ADDMEMBER   | 2017-06-14 08:03:58.872908 | 2017-06-14 09:17:02.719318 | x  
    ADDMEMBER   | 2017-06-14 09:28:23.343281 | 2017-06-14 09:46:50.189582 | x

我不知道如何做到這一點。任何幫助將不勝感激。

來源

2017-06-14 Pandora

你能告訴我們，你試過SQL以及它給出的結果？ – SaggingRufus

請描述你如何將addmember和removemembers相互配對。數據中沒有會話標識符，只有用戶標識。如果只能使用用戶和時間信息，那麼是否可以在沒有removemember事件的情況下結束會話？ – Shadow

假設ADDMEMBER，REMOVEMEMBER事件總是配對，那麼你可以使用下面的查詢來獲取Login，Logoff時間：

SELECT 'ADDMEMBER', 
     MIN(`time`) AS Login, 
     MAX(`time`) AS Logoff, 
     user 
FROM (    
    SELECT event, `time`, id, user, 
      @grp := IF(event = 'ADDMEMBER', @grp + 1, @grp) AS grp     
    FROM mytable 
    CROSS JOIN (SELECT @grp := 0) AS v 
    ORDER BY `user`, `time`) AS t 
GROUP BY user, grp;

Demo here

來源

2017-06-14 12:04:08

條件行以單行的MySQL

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