CODEWITHSUNDEEP
sqloracle10g
Gyanendra Kumar
Gyanendra Kumar

Reputation: 39

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.

Upvotes: 0

Views: 5566

Answers (3)

mm759
mm759

Reputation: 1424

You can use subqueries for retrieving first three and last three rows. The top level statement can delete them. You need something that defines the order like the employee number.

DELETE FROM EMP
WHERE EMPNO IN (
  SELECT EMPNO
  FROM (
    SELECT EMPNO
    FROM EMP
    ORDER BY EMPNO ASC
  ) 
  WHERE ROWNUM <= 3
) OR EMPNO IN (
  SELECT EMPNO
  FROM (
    SELECT EMPNO
    FROM EMP
    ORDER BY EMPNO DESC
  ) 
  WHERE ROWNUM <= 3
)

Upvotes: 0

Henrique Baldin
Henrique Baldin

Reputation: 11

Try this:

DELETE FROM  YourTable
WHERE ID IN
(
    SELECT TOP 3 ID FROM YourTable ORDER BY ID ASC
    UNION
    SELECT TOP 3 ID FROM YourTable ORDER BY ID DESC
)

This will select the first 3 and the last 3 registers from your table considering the ID`s. But be sure that no one has modified the table while you were coding, because you may delete registers that you do not want to.

Upvotes: 1

Gordon Linoff
Gordon Linoff

Reputation: 1269853

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
                       );

Upvotes: 2

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