DB2 group by month和count with multiple where子句

时间:2015-02-05 20:14:45

标签: sql count group-by db2

我有以下名为INCIDENT的DB2表

ticketid     Createdon     Severity
1            2012-01-01    1
2            2012-01-10    2
3            2012-01-15    2
4            2012-01-20    3
5            2012-01-29    3
6            2012-02-06    3
7            2012-02-15    3
8            2012-02-20    3
9            2012-02-20    4
10           2012-02-21    3

我试图获得的结果:

Month      Sev1   Sev2   Sev3   Sev4
====================================
2012-01       1      2      2      0
2012-02       0      0      4      1

到目前为止我有这个:

select to_char(INCIDENT.CREATEDON, 'YYYY-MM') as month, 
count(case when severity = 1 then 1 else 0 end) as SEV1,
count(case when severity = 2 then 1 else 0 end) as SEV2
from INCIDENT group by to_char(INCIDENT.CREATEDON,'YYYY-MM')

但是这给了我两个栏目中的所有事件......

Month      Sev1   Sev2   Sev3   Sev4
====================================
2012-01      11     11     11     11
2012-02      16     16     16     16

我没有得到什么概念?我认为这是可行的,但无法解决这个问题......

1 个答案:

答案 0 :(得分:1)

我明白了!当然我在发布我的问题之后想出来了......

select to_char(INCIDENT.CREATEDON, 'YYYY-MM') as month, 
sum(case when severity = 1 then 1 else 0 end) as sev1,
sum(case when severity = 2 then 1 else 0 end) as sev2,
sum(case when severity = 3 then 1 else 0 end) as sev3,
sum(case when severity = 4 then 1 else 0 end) as sev4
from INCIDENT 
where (createdon >=  current_timestamp - (minute(current_timestamp) minute) - (hour(current_timestamp) -1) hours - ( day(current_date) - 1 ) days - 13 month ) group by to_char(INCIDENT.CREATEDON,'YYYY-MM')