Detect and Set Column values between rows - sql

Question

I have a table relating to products:
PRD_SLD table
ID DATE SALE_IND
3 2012 0
3 2013 0
3 2014 1
3 2014 1
3 2015 1
3 2016 0
3 2017 1
I would like my final results to look like this:
PRD_SLD table
ID DATE SALE_IND STRT END
3 2012 0 2012 2014
3 2013 0 2012 2014
3 2014 1 2014 2016
3 2014 1 2014 2016
3 2015 1 2014 2016
3 2016 0 2016 2017
3 2017 1 2017 2017
I currently have a working CTE for retrieving the rows in which the values change. this CTE returns this:
PRD_SLD table
ID DATE SALE_IND
3 2012 0
3 2014 1
3 2016 0
3 2017 1
So it returns the first instance of the value in the table, and returns every time the SALE_IND changes.
Is there a way to create a start and end date based off of the date column? I am still very new to this and was enrolled in an advanced course. I'm sure there is a better way to complete this but is there a way to do it with the CTE results i have created? I know there is a between function but i don't know how to implement it into this query

Answer 1

One method is to define groups of adjacent records. You don't have a solid ordering of the rows, but you do have just enough information for this to work -- assuming the indicator is constant in each year.
select t.*,
min(year) over (partition by id, sale_ind, seqnum - seqnum_s) as min_year,
max(year) over (partition by id, sale_ind, seqnum - seqnum_s) as max_year
from (select t.*,
dense_rank() over (partition by id order by date) as seqnum,
dense_rank() over (partition by id, sale_ind order by date) as seqnum_s
from t
) t;