因此,当我尝试加载包含9位数字的数据文件时,脚本也将加载9位行。我只希望加载10位数字的行。问题是我希望将sql加载程序设置为仅接受正好为10位数的行。
据我所知,你做不到; SQL * Loader无法执行此操作。仅当WHEN
子句接受像length
这样的函数时,它才会非常好。但是,事实并非如此。
我能想到的最简单的选择是全部加载它们,然后删除不需要的行。例如:
表说明:
SQL> desc test
Name Null? Type
----------------------------------------- -------- ----------------------
TEL VARCHAR2(10)
SQL> select * From test;
no rows selected
控制文件:
load data
infile *
replace
into table test
(
tel char(10)
)
begindata
1234567890
986532554
3216549878
21212
运行:
SQL> $sqlldr scott/tiger control=test19.ctl log=test19.log
SQL*Loader: Release 11.2.0.2.0 - Production on Pon Svi 4 21:46:17 2020
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
Commit point reached - logical record count 4
SQL> select * From test;
TEL
----------
1234567890
986532554
3216549878
21212
删除您不想要的内容:
SQL> delete from test where length(tel) < 10;
2 rows deleted.
SQL> select * From test;
TEL
----------
1234567890
3216549878
SQL>
另一个可以静默地跳过不需要的值的选项是数据库触发器。为此,请基于表和一个代替触发器创建一个视图:
SQL> truncate table test;
Table truncated.
SQL> create or replace view v_test as select * From test;
View created.
SQL> create or replace trigger trg_bivt
2 instead of insert on v_test
3 for each row
4 begin
5 if length(:new.tel) < 10 then
6 null;
7 else
8 insert into test (tel) values (:new.tel);
9 end if;
10 end;
11 /
Trigger created.
让我们尝试:
SQL> $sqlldr scott/tiger control=test19.ctl log=test19.log
SQL*Loader: Release 11.2.0.2.0 - Production on Pon Svi 4 21:52:59 2020
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
Commit point reached - logical record count 4
SQL> select * From test;
TEL
----------
1234567890
3216549878
SQL>
此选项很好,但是当您加载大量数据时,性能会受到影响。
还有另一个选择是外部表。它的好处是可以将源文件视为普通的Oracle表-您可以直接针对它编写查询。为了使用它,创建一个目录并向使用它的用户授予特权:
SQL> show user
USER is "SYS"
SQL> create directory ext_dir as 'c:\temp';
Directory created.
SQL> grant read, write on directory ext_dir to scott;
Grant succeeded.
SQL>
创建外部表:
SQL> show user
USER is "SCOTT"
SQL> create table test_ext
2 (tel varchar2(10))
3 organization external
4 (type oracle_loader
5 default directory ext_dir
6 access parameters (records delimited by newline
7 fields terminated by ','
8 (tel char(10))
9 )
10 location ('test.txt')
11 )
12 reject limit unlimited;
Table created.
SQL>
Test.txt内容:
1234567890
986532554
3216549878
21212
它起作用吗?
SQL> select * From test_ext;
TEL
----------
1234567890
986532554
3216549878
21212
SQL>
现在,仅插入要接受的行:
SQL> truncate table test;
Table truncated.
SQL> insert into test (tel)
2 select tel
3 from test_ext
4 where length(tel) = 10;
2 rows created.
SQL> select * from test;
TEL
----------
1234567890
3216549878
SQL>
此选项的唯一缺点是,您必须有权访问(通常而言)位于数据库服务器上的目录,因此您必须与DBA交谈。
如您所见,有很多选择,但都不是您想要的。