Answer / nagendra

select empno, count(empno)
from emp
group by empno
having count(empno) > 1;

Answer / santhi kandasamy

In Oracle,

select empno from emp where empno is not null
group by empno
having count(*) >1;

if the above query does not return any rows then you can
consider, empno having unique values.

Answer / eswar

select empno,count(empno)
from emp group by empno having count(empno)>1;

Answer / suresh somayajula

in rownum we will use < or <= operators only.

If any one knows this query pls send the answer.

Answer / biswajit rout

SELECT empno,count(*) FROM emp GROUP BY empno;

Answer / valli

select rowid from (
select emp_no, rownum() over (emp_no) as Rownum
from emp order_by emp_no,sal
) where rownum > 2

If this query returns no rows then we can say all the emp
numbers are indeed unique.

Regard,
Valli

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