Gyanendra Kumar Gyanendra Kumar - 1 month ago 10
SQL Question

Delete First 3 Rows & Last 3 Rows in Target Table

I want to delete first 3 rows and last 3 rows in the table.But using single query for deleting data from the table.I am using oracle 10g. Please give me solution for oracle 10g.

And my table is like:



SQL> SELECT * FROM EMP;

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10

14 rows selected.

I want output like this.

target
------

7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20



Thanks in advance.

Answer

Assuming that the ordering is based on EMPNO, then you can do:

delete from emp
   where emp.empno in (select empno
                       from (select empno,
                                    row_number() over (order by empno) as seqnum_asc,
                                    row_number() over (order by empno desc) as seqnum_desc
                             from emp
                            ) e
                        where seqnum_asc <= 3 or seqnum_sec <= 3
                       );