This is tricky but most common question in Interviews. Popular question on employee table.
EMP => I am using only one table
Query:
SELECT COUNT(E.EMPID) FROM EMP E, EMP D WHERE E.WORKDEPT=D.WORKDEPT
RESULT: 298 , WE GOT COUNT OF EMPLOYEES
IF we know dept and emp tables ( 2 Tables)
SELECT COUNT(E.EMPID) FROM EMP E, DEPT D WHERE E.WORKDEPT=D.DEPT
RESULT: 298 , WE GOT COUNT OF EMPLOYEES