字段记录去重的问题
SQL语句如下:
SELECT
COUNT(distinct log.time_id) as logcount,
SUM(case when admit.admit_opinion='优' then 1 else 0 end) as best,
SUM(case when admit.admit_opinion='良' then 1 else 0 end) as good,
SUM(case when admit.admit_opinion='中' then 1 else 0 end) as middle,members.username
FROM members
LEFT JOIN userclass ON members.flag=userclass.flagid
LEFT JOIN log ON members.uid=log.userid
LEFT JOIN log_time ON log.time_id=log_time.tid
LEFT JOIN admit ON log.id=admit.logid
WHERE userclass.iswrite=1 AND log_time.end_date < curdate() AND log_time.year=".$year."
GROUP BY members.uid,admit.admit_flag
ORDER BY members.groupid,members.flag DESC,members.uid
现在的问题是admit表中有很多记录的logid是重复的(其它字段数据不同,只有logid相同),我只想统计出logid不同的记录数,也就是同样的logid只统计一次,然后用sum汇总出优、良、中来。这个语句怎么改?