What does this have to do with BI? Also, please post test data in the form of a datastep, as such this code is untested:
proc sql;
  create table want as 
  select a.id,
            a.date,
            b.date as last_date
  from   tablea a
  left join (select id,
                    max(date) as date 
             from   tableb 
             group by id) b
  on       a.id=b.id;
quit;
					
				
			
			
				
			
			
			
				
			
			
			
			
			
		What does this have to do with BI? Also, please post test data in the form of a datastep, as such this code is untested:
proc sql;
  create table want as 
  select a.id,
            a.date,
            b.date as last_date
  from   tablea a
  left join (select id,
                    max(date) as date 
             from   tableb 
             group by id) b
  on       a.id=b.id;
quit;
					
				
			
			
				
			
			
			
			
			
			
			
		You posted the question in the BI forum, but I didn't see anything relating to BI specifically. If so I can move to the general SAS questions area.
It's finally time to hack! Remember to visit the SAS Hacker's Hub regularly for news and updates.