Write a query to display alternate records from the employee table?

SELECT * FROM emp WHERE (rowid,1) IN (SELECT rowid,mod(rownum,2) FROM emp);

--odd number query

SELECT *
      FROM   ( SELECT rownum rn, empno, ename
               FROM emp
             ) temp
      WHERE  MOD(temp.rn,2) = 1

--even number query


SELECT *
      FROM   ( SELECT rownum rn, empno, ename
               FROM emp
             ) temp
      WHERE  MOD(temp.rn,3) = 0

select count(*), rownum
from emps
group by rownum
having mod(rowmum,2) = 1

output:-

1      1
1      3
1      5
1      7
1      8
.
.
.
.
.

select * from employeeswhere employee_id in (105,160,148,165,175,206);

Hi Guys,
 
You can use this query also

select * from employees where employee_id in (
select decode(mod(rownum,2),x,employee_id,null) emp_id from employees)
/

where x=0 for even records
where x=1 for odd   records

Regards,

Snehasish

To Display even row numbers
---------------------------
select * from emp where (rowid,0) in (select rowid,mod(rownum,2) from emp ) 

To Display odd row numbers
---------------------------
select * from emp where (rowid,1) in (select rowid,mod(rownum,2) from emp )

SELECT * FROM (SELECT ROWNUM RN, FIRST_NAME FROM EMPLOYEES) TEMP WHERE MOD (TEMP.RN, 2)=1;


CHANGE LAST NUMBER 1 TO 0 FOR EVEN NUMBERED ROWS.

Basically, in this, I used a subquary and selected all rows where RN was holding ROWNUM values, then outer SELECT was used to check with MOD function.

select ename,job from(select mod(rownum,2) as odd,ename,job from emp) where odd=1;
                   odd rows are retrive
     for even just replace as odd=0;
                    keep smiling(pavankumar_cherukuri@yahoo.com)

  1* select * from (select employee_id,last_name,salary,rownum rn from employees ) where mod(rn,2) = 0
SQL> /

EMPLOYEE_ID LAST_NAME                     SALARY         RN
----------- ------------------------- ---------- ----------
        101 Kochhar                        17000          2
        103 Hunold                          9000          4
        107 Lorentz                         4200          6
        141 Rajs                            3500          8
        143 Matos                           2600         10
        149 Zlotkey                        10500         12
        176 Taylor                          8600         14
        200 Whalen                          4400         16
        202 Fay                             6000         18
        206 Gietz                           8300         20

10 rows selected.

for even rows:-

select ename,empno, job, rownum from emp group by ename ,rownum ,empno,job having mod(rownum,2)=0


for odd rows please replace '0' with 1 then u get odd rows:-

select r, ename from(select rownum r,ename from emp) where mod(r,2)=1;

@manish dudhe

Your answer for even number query is wrong. The correct query is
SELECT temp.r, employee_id, first_name, last_name
FROM (SELECT rownum as r, employee_id, first_name, last_name FROM employees) temp
WHERE MOD(r,2) = 0;

Code
SELECT * FROM emp WHERE ROWID IN (SELECT DECODE(MOD(ROWNUM,2),0,ROWID, NULL) FROM emp);

Answer

Code
SELECT rownum
FROM TABLE
GROUP BY rownum
HAVING mod(rownum,2)=0