SQL时间参数计算

Question

我刚刚尝试创建活动报告的SQL新手，我在表上存储过程和触发器以记录登录和注销日期/时间。

我如何计算时间一些建议之后，从第一个日志先后在持续注销每天？

任何指导将不胜感激谢谢。

Answer 1

SELECT A.*, 
     DATEDIFF(second,B.firstloginonthatday,B.lastlogoutonthatday) AS time_elapsed 
    FROM YourTable A 
INNER JOIN 
    (  SELECT Z.USERID, 
        CONVERT(DATE,Z.DATE_TIME) AS ONLYDATE, 
        MIN(Z.DATE_TIME) AS firstloginonthatday, 
        MAX(Z.DATE_TIME) AS lastlogoutonthatday 
       FROM 
       (
        SELECT *, 
          ROW_NUMBER() 
          OVER 
          (PARTITION BY USERID,CONVERT(DATE,DATE_TIME) ORDER BY CASE WHEN action = 'logout' THEN DATE_TIME 
           ELSE NULL END 
          ) AS lastlogout_rn,    
          ROW_NUMBER() 
          OVER 
          (PARTITION BY USERID,CONVERT(DATE,DATE_TIME) ORDER BY CASE WHEN action = 'login' THEN DATE_TIME 
           ELSE NULL END 
          ) AS firstlogin_rn  
         FROM Yourtable 
       ) Z 
      WHERE Z.lastlogout_rn = 1 OR Z.firstlogin_rn = 1 
      GROUP BY Z.USERID,CONVERT(DATE,Z.DATE_TIME) 
    ) B 
    ON A.USERID = B.USERID 
    AND CONVERT(DATE,A.DATE_TIME) = B.ONLYDATE;