SELECT log_userId, sum(DATEDIFF(minute, logLogindate, logLogoutdate))
FROM login
GROUP BY log_userId
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essentitia preter non sans multiplicandum
Frågan#1
Jag vill visa hur lång tid varje person (log_userID) har varit inloggad totalt. Jag sparar bland annat logLogindate, logLogoutdate och log_userId i tabellen. Detta fungerar inte:
SELECT log_userId, DATEDIFF(minute, logLogindate, logLogoutdate)
FROM login
GROUP BY log_userId
Column login.logLogoutdate is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.
DBMS = SQL Server