替换电子邮件域

Question

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;
  /

Answer 1

您编写的代码没有多大意义。 太多的提取将不起作用（将两个列合并到一个变量中？）。

这是一个示例：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；它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>

游标FOR循环比您的尝试（创建游标和游标变量，打开游标，从游标中获取，小心退出循环，关闭游标）更容易维护。

但是，如果没有它就无法生存，那么您可以：

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。 不要为此使用游标。