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如何有条件的分步删除数据表中的记录

2013年03月06日 ⁄ 综合 ⁄ 共 1907字 ⁄ 字号 评论关闭

有时候我们需要分配删除数据表的一些记录,分批提交以减少对于Undo的使用,本文提供一个简单的存储过程用于实现该逻辑。
你可以根据你的需要进行适当调整,本例仅供参考:

SQL> create table test as select * from dba_objects;

Table created.

SQL> create or replace procedure deleteTab

2 /**

3 ** Usage: run the script to create the proc deleteTab

 4 ** in SQL*PLUS, type "exec deleteTab('Foo','ID>=1000000','3000');"

5 ** to delete the records in the table "Foo", commit per 3000 records.

6 ** Condition with default value '1=1' and default Commit batch is 10000.

7 **/

8 (

9 p_TableName in varchar2, -- The TableName which you want to delete from

10 p_Condition in varchar2 default '1=1', -- Delete condition, such as "id>=100000"

11 p_Count in varchar2 default '10000' -- Commit after delete How many records

12 )

13 as

14 pragma autonomous_transaction;

15 n_delete number:=0;

16 begin

17 while 1=1 loop

18 EXECUTE IMMEDIATE

19 'delete from '||p_TableName||' where '||p_Condition||' and rownum <= :rn'

20 USING p_Count;

21 if SQL%NOTFOUND then

22 exit;

23 else

24 n_delete:=n_delete + SQL%ROWCOUNT;

25 end if;

26 commit;

27 end loop;

28 commit;

29 DBMS_OUTPUT.PUT_LINE('Finished!');

30 DBMS_OUTPUT.PUT_LINE('Totally '||to_char(n_delete)||' records deleted!');

31 end;

32 /Procedure created.

SQL> insert into test select * from dba_objects;

6374 rows created.

SQL> /6374 rows created.

SQL> /6374 rows created.

SQL> commit;Commit complete.

SQL> exec deleteTab('TEST','object_id >0','3000')

Finished!

Totally 19107 records deleted!

PL/SQL procedure successfully completed.

很简单,但是想来也有人可以用到。

修正了一下,增加了2个缺省值,完整过程如下:

create or replace procedure deleteTab(
       p_TableName in varchar2,
       p_Condition in varchar2 default '1=1',
       p_Count in varchar2 default '10000' ) 
    as pragma autonomous_transaction;
    n_delete number:=0;
    begin while 1=1
    loop
    EXECUTE IMMEDIATE 'delete from '||p_TableName||' where '||p_Condition||' and rownum <= :rn'

    USING p_Count;
    if SQL%NOTFOUND
    then exit;
    else n_delete:=n_delete + SQL%ROWCOUNT;
    end if; commit; end loop; commit;
    DBMS_OUTPUT.PUT_LINE('Finished!');
    DBMS_OUTPUT.PUT_LINE('Totally '||to_char(n_delete)||' records deleted!');
    end;
 /  

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