我正在尝试创建一个报告,在3个时间段内计算:上个月,去年的那个月和今年的年份。
我之前使用了3个单独的查询,同时切换where子句,但我希望能够将所有3个组合成一个查询。
我已尝试过案例陈述,但似乎无法让它发挥作用。仅供参考,app_date
是YYYY-MM-DD
Select count(application_id)
from application_data a
where to_char(app_date, 'YYYYMM' = to_char(current_date, 'YYYYMM')-1
--where to_char(app_date, 'YYYYMM' = to_char(current_date, 'YYYYMM')-101
--where to_char(app_date, 'YYYY') = to_char(current_date, 'YYYY') and to_char(app_date, 'YYYYMM') <> to_char(current_date, 'YYYYMM')
样本数据:
App_ID App_date
123519 2018-02-17
123521 2018-02-18
123522 2018-02-19
123523 2018-02-23
123518 2019-01-15
123546 2019-02-21
123547 2019-02-22
123548 2019-02-15
123542 2019-02-02
期望的结果:
LastMonth YTD YoY
4 5 4
我想你想要条件聚合:
Select sum(case when to_char(app_date, 'YYYYMM' = to_char(current_date, 'YYYYMM')-1 then 1 else 0 end),
sum(case to_char(app_date, 'YYYYMM' = to_char(current_date, 'YYYYMM')-101 when then 1 else 0 end),
sum(case when to_char(app_date, 'YYYY') = to_char(current_date, 'YYYY') and to_char(app_date, 'YYYYMM') <> to_char(current_date, 'YYYYMM') then 1 else 0 end)
from application_data a