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2024-05-06
分别删除数据表记录的方法
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软件频道
编程学院
Sql Server
技巧运用
正文
很多情况下我们需要分别删除数据表的一些记录，分批来提交以此来减少对于Undo的使用，下面我们提供一个简单的存储过程来实现此逻辑。
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.
注释：在此实例中修正了一下,增加了2个缺省值,以下是具体过程:
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!');
注释：读者可以根据自己的实际情况来进行适当的调整。
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