You can definitely get Boolean value from a SELECT query, you just can't use a Boolean data-type.
You can represent a Boolean with 1/0.
CASE WHEN (10 > 0) THEN 1 ELSE 0 END (It can be used in SELECT QUERY)
SELECT CASE WHEN (10 > 0) THEN 1 ELSE 0 END AS MY_BOOLEAN_COLUMN
FROM DUAL
Returns, 1 (in Hibernate/Mybatis/etc 1 is true). Otherwise, you can get printable Boolean values from a SELECT.
SELECT CASE WHEN (10 > 0) THEN 'true' ELSE 'false' END AS MY_BOOLEAN_COLUMN
FROM DUAL
This returns the string 'true'
.