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如何有条件的分步删除数据表中的记录
作者：eygle |【转载时请务必以超链接形式标明文章原始出处和作者信息及本声明】链接：http://www.eygle.com/archives/2005/02/ecioioaeoeeeioe.html
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, -- The TableName which you want to delete from
p_Condition in varchar2 default '1=1', -- Delete condition, such as "id>=100000"
p_Count in varchar2 default '10000' -- Commit after delete How many records
)
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;
/
|
By eygle on 2005-02-22 16:27 | Comments (5) | Posted to HowTo | SQL.PLSQL | Edit |Pageviews:
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留言 (5)
赞一个，最近我就碰到了这个问题。
Posted by: fans at May 5, 2005 4:48 PM
删除条件为空时，会出错。呵呵
Posted by: karson at June 14, 2005 2:13 PM
条件为空时，可以加个‘1＝1’代替。
Posted by: find_ufo at July 19, 2005 9:47 AM
修正了一下,增加了2个缺省值.
Posted by: eygle at November 19, 2005 8:40 PM
问下老大，为什么要用自治事务呢？
Posted by: waityou at January 23, 2006 3:47 PM
