SQL> Select *from emp where rowid = (select max(rowid) from emp where rownum <= 4);
Or
SQL> Select *from emp where rownum <= 4 minus select *from emp where rownum <= 3;
2) To find duplicate rows
SQL> Select *from emp where rowid in (select max(rowid) from emp group by empno,
ename, mgr, job, hiredate, comm, deptno, sal);
Or
SQL> Select empno,ename,sal,job,hiredate,comm , count(*) from emp group by
3) To delete duplicate rows
SQL> Delete emp where rowid in (select max(rowid) from emp group by
empno,ename,mgr,job,hiredate,sal,comm,deptno);
4) To find the count of duplicate rows
SQL> Select ename, count(*) from emp group by ename having count(*) >= 1;
5) How to display alternative rows in a table?
SQL> select *from emp where (rowid,0) in (select rowid,mod(rownum,2) from emp);
6) Getting employee details of each department who is drawing maximum sal?
SQL> select *from emp where (deptno,sal) in
( select deptno,max(sal) from emp group by deptno);
7) How to get number of employees in each department , in which department is having more than 2500 employees?
SQL> Select deptno,count(*) from emp group by deptno having count(*) >2500;
9) To reset the time to the beginning of the day
SQL> Select to_char(trunc(sysdate),’dd-mon-yyyy hh:mi:ss am’) from dual;
10) To find nth maximum sal
SQL> Select *from emp where sal in (select max(sal) from (select *from emp order by sal)
where rownum <= 5);
