チェック制約

Question

は、次の表にチェック制約を追加しようとすると：

CREATE TABLE TEST_A 
(
    NAME VARCHAR(55), 
    Country VARCHAR(50) 
) 

ALTER TABLE TEST_A 
    ADD CONSTRAINT CK_GBR_TO_IND 
     CHECK (Country = CASE WHEN 'GBR' THEN 'IND' ELSE COUNTRY END); 

私は、次のようなエラーになっています：

Msg 4145, Level 15, State 1, Line 2
An expression of non-boolean type specified in a context where a condition is expected, near 'THEN'.

Answer 1

を代わりにトリガーを試してみてください。.. You Can't use Check Constraint to change values ...

create trigger trg_test 
on yourtable 
instead of insert 
as 
Begin 

insert into yourtable--assuming it has only country column 
select case when country='GBR' then 'IND' 
else country end 
from Inserted 

end 

Answer 2

ALTER TABLE TEST_A ADD CONSTRAINT CK_GBR_TO_IND 
CHECK (Country IN('GBR', 'IND'));