Question

我有桌子：

STATUS  DEFECT   DATE

CLOSED  IP       01.01.2012 
CLOSED  TV       03.03.2012
CLOSED  ADSL     05.05.2012
CLOSED  ADSL     11.01.2012 
CLOSED  TV       15.01.2012
NEW     TV         
NEW     TV

我希望按月计算每个特定缺陷的计数。考虑的状态是CLOSED

我想成为的结果表：

MONTH     TV  ADSL  IP
January   1   1     1
March     1   0     0
May       0   1     0

我正在使用db2数据库，因此显示月份的部分是：

select case month(timestamp_iso(DATE))
        when 1 then 'January'
        when 2 then 'February'
        when 3 then 'March'
        when 4 then 'April'
        when 5 then 'May'
        when 6 then 'Jun'
        when 7 then 'July'
        when 8 then 'August'
        when 9 then 'September' 
        when 10 then 'October'
        when 11 then 'November'
        when 12 then 'December'
    end as Month

from TABLE
where  STATUS='CLOSED'
group by month(timestamp_iso(DATE))
order by month(timestamp_iso(DATE))

所以我只需要添加这部分来计算。谢谢

Answer 1

您可以使用另一个案例陈述来计算缺陷类别，该陈述会将计数限制在一个类别中的缺陷：

select case month(timestamp_iso(DATE))
        when 1 then 'January'
        when 2 then 'February'
        when 3 then 'March'
        when 4 then 'April'
        when 5 then 'May'
        when 6 then 'Jun'
        when 7 then 'July'
        when 8 then 'August'
        when 9 then 'September' 
        when 10 then 'October'
        when 11 then 'November'
        when 12 then 'December'
    end as Month,
    count (case when defect = 'TV' then 1 end) TV,
    count (case when defect = 'ADSL' then 1 end) ADSL,
    count (case when defect = 'IP' then 1 end) IP
from TABLE
where  STATUS='CLOSED'
group by month(timestamp_iso(DATE))
order by month(timestamp_iso(DATE))

SQL MULTIPLE COUNTS，GROUP BY MONTHS

1 个答案: