Wana capture current product details with previous product details

[nitink26]

Hi,

I need help on below query -

I have below dataset. From this data I need to capture Client, Current_Product, First Instance of Previous_product (If there are any - Highlighted in blue colour) and PREVIOUS_PRODUCT_year_month.

Data is sorted by client, descending Year_month

Data -

CLIENT	Current_Product	YEAR_MONTH
1	ABC	202111
1	ABC	202110
1	ABC	202109
1	ABC	202108
1	ABC	202107
2	CDE	202111
2	CDE	202110
2	CDE	202109
2	CDF	202108
2	CDE	202107

Output I am looking for - 

CLIENT	Current_Product	PREVIOUS_PRODUCT	PREVIOUS_PRODUCT_year_month
1	ABC
2	CDE	CDF	202108

Thanks!

[s_lassen · Accepted solution]

Something like this, perhaps?

Data want;
  do until(last.client);
    set have(rename=(Current_Product=Product Year_month=Previous_Product_Year_month));
    by client Product notsorted;
    if first.client then 
      Current_Product=Product;
    else if first.product then do;
      Previous_Product=Product;
      output;
      end;
   end; 
   keep client Current_Product Previous_Product Previous_Product_Year_month;
run;