Question

I want to compare content of 15 columns in two rows.
I am using db2 9 with jdbc.
Can I use a sql to get a result like “match or not match”

---

And How can I get columns differs?

Answer 1

You can use the EXCEPT operator to do this.

In the example below, I’m using common table expressions to fetch a the single rows (assuming, in this case, that id is the primary key.

with r1 as (select c1, c2, ..., c15 from t where id = 1),
     r2 as (select c1, c2, ..., c15 from t where id = 2)
select * from r1
except 
select * from r2

If this returns 0 rows, then the rows are identical. If it returns a row, then the two rows differ.

If you really want the result to be ‘MATCH’ or ‘NOT MATCH’:

with r1 as (select c1, c2, ..., c15 from t where id = 1),
     r2 as (select c1, c2, ..., c15 from t where id = 2),
     rs as (select * from r1 except select * from r2)
select
   case when count(*) = 0 then 'MATCH' 
        else 'NOT MATCH' 
        end as comparison 
from
   rs;