Oracle Database Can set Constraint for Upper Case Values?

Question

Is there anyway that we can set a constraint in database table level to have upper or lower case values for certain columns? When we create a table, we can set NOT NULL to avoid having null values on a column. Same way, can we do that for either uppercase or lower case?

Answer 1

You can do that using a check constraint:

create table foo
(
   only_lower varchar(20) not null check (lower(only_lower) = only_lower),
   only_upper varchar(20) not null check (upper(only_upper) = only_upper)
);