我正在尝试将输入的域名更改为新域名，例如，“ hotmail.com”变为“ outlook.com”。我相信我在正确的轨道上，只是我的子字符串关闭了。
CREATE OR REPLACE PROCEDURE PR_ChangeDomain
(P_Email_Address varchar2)
IS
Cursor C_Email IS
Select Email_Address, Broker_Number
From Customer
Where Email_Address = P_Email_Address;
V_Email varchar2(50);
BEGIN
Open C_Email;
Fetch C_Email into V_Email;
While C_Email%FOUND LOOP
Update Customer
Set Email_Address = SUBSTR((Email_Address), V_Email)
Where Email_Address = P_Email_Address;
Fetch C_Email into V_Email;
End Loop;
Close C_Email;
End PR_ChangeDomain;
/
答案 0 :(得分：1)
您编写的代码没有太大意义；过多的提取操作不起作用（将两个列合并到一个变量中？）。
这是一个例子：一个测试表：
SQL> create table test (email varchar2(30));
Table created.
SQL> insert into test
2 select 'lf@hotmail.com' from dual union all
3 select 'bigfoot@net.hr' from dual union all
4 select 'stack@gmail.com' from dual union all
5 select 'overflow@gmail.com' from dual;
4 rows created.
如何从中拆分域部分（以下SELECT的第二列），并将电子邮件地址更新到新域（第三列）：
SQL> select email,
2 substr(email, instr(email, '@') + 1) domain,
3 replace(email,
4 substr(email, instr(email, '@') + 1),
5 'new_domain.com'
6 ) result
7 from test;
EMAIL DOMAIN RESULT
------------------------- --------------- -------------------------
lf@hotmail.com hotmail.com lf@new_domain.com
bigfoot@net.hr net.hr bigfoot@new_domain.com
stack@gmail.com gmail.com stack@new_domain.com
overflow@gmail.com gmail.com overflow@new_domain.com
SQL>
让我们仅将Gmail电子邮件地址更新为新域：
SQL> update test set
2 email = replace(email,
3 substr(email, instr(email, '@') + 1),
4 'new_domain.com'
5 )
6 where substr(email, instr(email, '@') + 1) = 'gmail.com';
2 rows updated.
SQL> select * From test;
EMAIL
-------------------------
lf@hotmail.com
bigfoot@net.hr
stack@new_domain.com
overflow@new_domain.com
SQL>
如果要将其转换为过程，没问题：
SQL> rollback;
Rollback complete.
SQL> create or replace procedure p_change_domain
2 (par_old_domain in varchar2,
3 par_new_domain in varchar2)
4 is
5 begin
6 update test set
7 email = replace(email,
8 substr(email, instr(email, '@') + 1),
9 par_new_domain
10 )
11 where substr(email, instr(email, '@') + 1) = par_old_domain;
12 end;
13 /
Procedure created.
SQL> exec p_change_domain('gmail.com', 'new_domain_2.com');
PL/SQL procedure successfully completed.
SQL> select * From test;
EMAIL
-------------------------
lf@hotmail.com
bigfoot@net.hr
stack@new_domain_2.com
overflow@new_domain_2.com
SQL>
如果您非常想使用游标（我不知道您为什么要这样做，这可能是效率最低的选择），请执行以下操作：
SQL> rollback;
Rollback complete.
SQL> create or replace procedure p_change_domain
2 (par_old_domain in varchar2,
3 par_new_domain in varchar2)
4 is
5 begin
6 for cur_r in (select email from test
7 where substr(email, instr(email, '@') + 1) = par_old_domain
8 )
9 loop
10 update test set
11 email = replace(email,
12 substr(email, instr(email, '@') + 1),
13 par_new_domain
14 )
15 where email = cur_r.email;
16 end loop;
17 end;
18 /
Procedure created.
SQL> exec p_change_domain('gmail.com', 'new_domain_3.com');
PL/SQL procedure successfully completed.
SQL> select * From test;
EMAIL
-------------------------
lf@hotmail.com
bigfoot@net.hr
stack@new_domain_3.com
overflow@new_domain_3.com
SQL>
Cursor FOR循环比您尝试的要容易维护（创建游标和游标变量，打开游标，从中获取游标，注意退出循环，关闭游标）。
但是，如果您不能没有它，那就去：
SQL> rollback;
Rollback complete.
SQL> create or replace procedure p_change_domain
2 (par_old_domain in varchar2,
3 par_new_domain in varchar2)
4 is
5 cursor c1 is
6 select email from test
7 where substr(email, instr(email, '@') + 1) = par_old_domain;
8 c1r c1%rowtype;
9 begin
10 open c1;
11 loop
12 fetch c1 into c1r;
13 exit when c1%notfound;
14
15 update test set
16 email = replace(email,
17 substr(email, instr(email, '@') + 1),
18 par_new_domain
19 )
20 where email = c1r.email;
21 end loop;
22 close c1;
23 end;
24 /
Procedure created.
SQL> exec p_change_domain('gmail.com', 'new_domain_4.com');
PL/SQL procedure successfully completed.
SQL> select * From test;
EMAIL
-------------------------
lf@hotmail.com
bigfoot@net.hr
stack@new_domain_4.com
overflow@new_domain_4.com
SQL>
我的建议？如果可能，请使用纯SQL。或第一个PL / SQL过程。请勿为此使用游标。