我有下表:
MobileNumber LocID
a 2
b 3
a 2
b 3
b 4
c 5
etc
一个手机号码可以是重复的并且具有不同的LocID。我想得到只存在于一个LocID中的手机列表(在本例中为"a"one_answers"c")。我试了以下几种,但没有成功。有什么帮助吗?
select MobileNumber, count(*)
from table1
where timestamp > '2012-03-01 00:00'
group by MobileNumber, LocID
having count(*) = 1;
尝试:
select MobileNumber, count(*)
from table1
where timestamp > '2012-03-01 00:00'
group by MobileNumber
having count(distinct LocID) = 1;