How to get data for current month, previous month and same month(current month) previous year?

[cggpai]

I have to get data for an incured date which should have current month, previous month and same month(current month) previous year? 

I need to get data for these three months for comparison.

Example : 2017-12-01, 2017-11-01 and 2016-12-01

Any idea or help will be really appreciated.

Thank you

[dnoeth]

A combination of ADD_MONTHS plus TRUNC/LAST_DAY...

[cggpai]

Sorry! could you please elaborate? Thank you.

[GJColeman]

See the SQL Functions manual at info.teradata.com for your release of Teradata.

select trunc(date'2017-12-22','RM') (format'y4-mm-dd')
    ,add_months(trunc(date'2017-12-22','RM'),-1)
    ,add_months(trunc(date'2017-12-22','RM'),-12);