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create table TableA(Id int, Function varchar(10));
insert into TableA(Id, Function) values
(1, 'code1'), (2, 'code2'), (3, 'code3'), (4, 'code4');
create table TableB(Id int, Function varchar(10));
insert into TableB(Id, Function) values
(1, 'code1'), (2, 'code4'), (3, 'code5');
select a.*,
exists (select 1 from TableB b where b.function = a.function) compare
from TableA a
| Id | Function | compare |
|---|---|---|
| 1 | code1 | 1 |
| 2 | code2 | 0 |
| 3 | code3 | 0 |
| 4 | code4 | 1 |
select a.*,
case
when exists (select 1 from TableB b where b.function = a.function) then 'true'
else 'false'
end compare
from TableA a
| Id | Function | compare |
|---|---|---|
| 1 | code1 | true |
| 2 | code2 | false |
| 3 | code3 | false |
| 4 | code4 | true |