select eempideename from emp e left join holiday h on eempid=hempid where eempid is null;

This query will select all employees (e.empid and e.ename) who did not take any holidays (left join with holiday table where empid is null).

However, the logic of this query is incorrect. If an employee did take a holiday, their empid will not be null in the holiday table and therefore the left join will not return null. To get all employees who did not take a holiday, the query should be:

SELECT e.empid, e.ename FROM emp e LEFT JOIN holiday h ON e.empid=h.empid WHERE h.empid IS NULL;