我要运行的查询：
SELECT date_trunc('month',UA.activity_date),SUM(UA.points) FROM user_activity UA
WHERE UA.activity_date > '01/01/2014' AND UA.activity_date < '12/31/2014'
GROUP BY date_trunc('month',UA.activity_date)
ORDER BY date_trunc('month',UA.activity_date)
预期成绩：
03/01/2014 00:00:00 66.04000000000000000
05/01/2014 00:00:00 13.50000000000000000
07/01/2014 00:00:00 27.00000000000000000
08/01/2014 00:00:00 26.00000000000000000
09/01/2014 00:00:00 13.50000000000000000
当我使用Hibernate运行该查询时，出现此错误：
ERROR: column "useractivi0_.activity_date" must appear in the GROUP BY clause or be used in an aggregate function
为了解决这个问题，我将上面的查询修改为：
SELECT date_trunc('month',UA.activity_date),SUM(UA.points) FROM user_activity UA
WHERE UA.activity_date > '01/01/2014' AND UA.activity_date < '12/31/2014'
GROUP BY date_trunc('month',UA.activity_date),***UA.activity_date***
ORDER BY date_trunc('month',UA.activity_date)
但是，结果是错误的：
03/01/2014 00:00:00 25.40000000000000200
03/01/2014 00:00:00 …