Question

我想删除表中的前3行和后3行。但是使用单个查询从表中删除数据。我正在使用oracle 10g。请给我oracle 10g的解决方案。

我的桌子就像：


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

提前致谢。

Answer 1

假设订购基于EMPNO，那么您可以这样做：

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
                       );

Answer 2

试试这个：

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
)

这将根据ID来选择表格中的前3个和最后3个寄存器。但是请确保在编码时没有人修改过表格，因为你可能会删除你不想要的寄存器。

Answer 3

您可以使用子查询来检索前三行和后三行。顶级语句可以删除它们。您需要定义订单的内容，例如员工编号。

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
)

删除前3行＆amp;目标表中的最后3行

3 个答案: