如何从 Db2 中的日期列生成 FY

Question

I have one Column In my Db2 table in which I have data in 'YYYYMMDD' format. I need to Create Financial Year from this column,so If month is in Jan,Feb or March then in Fy I need to generate as Prev year '-' current year else current year '-' next Year.

In My source Table I have MTH_YR column as '20210101'.I am Able to generate date from this column as 2021-01-01 now from this column i need to genarate Fy as 2020-2021 I am writing below Query

    select substring(MTH_YR, 1, 4) || '-' || substring(MTH_YR, 5, 2) || '-' || 
    substring(MTH_YR, 7, 2)  as date_format,
    CASE WHEN month(to_date(date_format)) IN (01,02,03) THEN 
    CONCAT(CONCAT(year(to_date(date_format))-1,'-'),substr(year(to_date(date_format)),3,4)) 
    ELSE 
    CONCAT(CONCAT(year(to_date(date_format)),'-'),SUBSTR(year(to_date(date_format))+1,3,4))
    end as FY from schemaname.Tablename;

But Getting Below Error.

    "FY" is not valid in the context where it is used.. SQLCODE=-206, SQLSTATE=42703, DRIVER=4.24.92

Can someone Please Guide me How should I Implement the same.

Answer 1

If you stored your date as a date , you would simply subtract 3 months and take the year:

select year(add_months(date_col, -3)) as fiscal_year

You can make this a string representation if you prefer:

select year(add_months(date_col, -3)) || '-' || (year(add_months(date_col, -3)) + 1)

If your date is not stored as a date, you should fix the data . But absent that, you can convert it in the expression.