sql合并chenge选择大小写

Question

I have 2 tables and want to get the row sum from 2 tables with conditions the result to be like this for example sh2 : 19 + 5 + 11 + 5 = 40 for each name calculate them all in a table i use that code

select name, sum(total) total from 
(select name, sum(coalesce(sk,ss)) total
 from table1
 group by name
 union all
 select name, sum(coalesce(sk,ss)) total
 from table2
 group by name
) t
group by name

but i want use select and case for that code

Answer 1

select name,SUM(total)total from(
      select name,sum(case when sk>0 then sk else ss end )total from majale group by name
      union all
      select name,sum(case when sk>0 then sk else ss end )from ketab group by name
      union all
      select name,sum(case when sk>0 then sk else ss end )from savabegh group by name
      )t
      group by name