select NFast_No from Web_FTT_Param where getdate() between Begin_date and End_date


select top 100 cancel_month, dateadd(day, -day(cancel_month), cancel_month) as lastmonth
from tbl_customer_cancellation


update tbl_customer_cancellation
set lastactivemonth = dateadd(day, -day(cancel_month), cancel_month)


--增減月份時，統一以每月1日為基準，避免注意大小月份日期不一，增減以後造成錯誤。
update tbl_customer_cancellation
set First4Month = dateadd(day, -1, dateadd(month, 3, dateadd(day, -day(pc_date)+1, pc_date)))
,Last4Month = dateadd(day, -1, dateadd(month, -3, dateadd(day, -day(cancel_month)+1, cancel_month)))

select top 100 cancel_month
,dateadd(day, -1, dateadd(month, -3, dateadd(day, -day(cancel_month)+1, cancel_month)))
,pc_date
,dateadd(day, -1, dateadd(month, 3, dateadd(day, -day(pc_date)+1, pc_date)))
from tbl_customer_cancellation

select top 100 pc_date, first3month, last4month, lastactivemonth
from tbl_customer_cancellation