在触发器中检查将来的日期

Question

I want to launch a trigger if a user try to replace current date with a future date.But subquery might not allowed in trigger. How can i solve this issue? Any suggestion....

  CREATE OR REPLACE TRIGGER check_join_date
        BEFORE UPDATE OF join_date ON DOCTOR
        FOR EACH ROW
        WHEN (NEW.join_date > (SELECT CURRENT_DATE+1 FROM DUAL) )
    BEGIN
        RAISE_APPLICATION_ERROR(-20509,'Do not Enter Future Date..');
    END check_join_date;
    /

I am getting this error after running this code in Oracle.

ORA-02251: subquery not allowed here

Answer 1

test this

CREATE OR REPLACE TRIGGER check_join_date
        BEFORE UPDATE OF join_date ON DOCTOR
        FOR EACH ROW
        WHEN (NEW.join_date > CURRENT_DATE+1)
    BEGIN
        RAISE_APPLICATION_ERROR(-20509,'Do not Enter Future Date..');
    END check_join_date;
    /