MySQL工作日/周末计数-第二部分

SELECt
fname,
MonTH(eventDate),
SUM(IF(WEEKDAY(eventDate) < 5,1,0)) AS WeekdayCount,
SUM(IF(WEEKDAY(eventDate) >= 5,1,0)) AS WeekendCount
FROM eventcal AS e
LEFT JOIN users AS u ON e.primary = u.username
GROUP BY fname, MonTH(eventDate);

您要在SELECT中进行汇总（在这种情况下为SUM），然后按希望的方式按GROUP BY汇总（按fname，按MONTH）。