How to get a calculated field in SELECT comparing with SYSDATE

Question

How can I build this select in Oracle:

SELECT DATETYPE_FIELD, DATETYPE_FIELD < SYSDATE AS IS_ON_DATE FROM MYTABLE

DATETYPE_FIELD is a DATE field. I want to get something like TRUE/FALSE in calculated IS_ON_DATE field. USING that select still get an error in ORACLE.

How can this be done?

Answer 1

There is no boolean type in Oracle. You can use 1 or 0 to denote true or false like this:

select DATETYPE_FIELD,
    case 
        when DATETYPE_FIELD < SYSDATE
            then 1
        else 0
        end as IS_ON_DATE
from MYTABLE

or string "true" and "false"

select DATETYPE_FIELD,
    case 
        when DATETYPE_FIELD < SYSDATE
            then 'true'
        else 'false'
        end as IS_ON_DATE
from MYTABLE