这条SQL
SELECT *,SUM(tuanke_time.time) AS total_time FROM `tuanke_time` LEFT JOIN tuanke_student ON tuanke_student.Sid = tuanke_time.studentID WHERE total_time > 100 GROUP BY tuanke_time.studentID
加上where就报错说不存在total_time列，但是我看了明明存在啊
三叔2016-11-19 15:09:29
total_time 是你给SUM(tuanke_time.time)取得别名，数据库表字段本身没有这列吧。
查询total_time > 100,你可以试试
SELECT * FROM `tuanke_time` LEFT JOIN tuanke_student ON tuanke_student.Sid = tuanke_time.studentID GROUP BY tuanke_time.studentID having SUM(tuanke_time.time) > 100;
