本来想统计一个游戏内测的激活号分发过几次和每次分到的用户人数
select distinct distributeTime from opentest_code
只能得到激活码的分发的时间，也就是说要得到每次(distributeTime)时间的用户数还得想想办法
select distinct distributeTime,count(*) from opentest_code
先弱智 一回，TEST一下也好，果然MySQL报错，没通过，不过同时出现提示：
Mixing of GROUP columns (MIN(),MAX(),COUNT()...) with no GROUP columns is illegal if there is no GROUP BY clause
看样子他是查觉到有人要查统计情况，提示group by
呵呵，原来如此，group by 以某个字段为群来分！
select distributeTime,count(*) from opentest_code GROUP BY distributeTime)
这样也对了~~呵呵
看来
select distinct distributeTime from opentest_code
select distributeTime from opentest_code GROUP BY distributeTime
意义是一样的，，，
呵呵，
