Question

如果今天的日期在表ABC的开始日期和结束日期之间，我需要编写一个过程来更新表Xyz的列。

table ABC

    fin_cycle    start_date   end_date    account_class
    ----------------------------------------------------

    F2018        27-05-2020    29-05-20    2003

table xyz
account_no    account_class  ac_no_dr

1234           2003             Y

当我今天运行该过程时，如果今天的日期在表ABC的开始日期和结束日期之间，则该过程会将ac_no_dr列更新为Y，否则它将更新该列为N。我已经准备好此框架。

Create Or Replace PROCEDURE pr_no_debit
     Cursor c_Today(start_date, end_Date) is
     Select Today from sttm_branch  where today between start_Date and end_Date;

   l_No_Debit_List   ABC%ROW_TYPE;
   Begin



     For c_Today(l_No_Debit_List.start_Date,l_No_Debit_List.end_Date) Loop  


       Update XYZ set ac_no_DR='Y' where account_class=l_No_Debit_List.account_class;

   End Loop;

     -- At the end of the period Change No_Debit to 'N'

   End pr_no_debit;

Answer 1

这里是一个选项：merge。（今天是2020年5月27日，介于abc表中存储的开始日期和结束日期之间。）

样本数据：

SQL> select * From abc;

FIN_C START_DATE END_DATE   ACCOUNT_CLASS
----- ---------- ---------- -------------
F2018 27.05.2020 29.05.2020          2003

SQL> select * From xyz;

ACCOUNT_NO ACCOUNT_CLASS A
---------- ------------- -
      1234          2003

合并语句：

SQL> merge into xyz a
  2    using (select account_class,
  3                  case when sysdate between start_date and end_date then 'Y'
  4                       else 'N'
  5                  end ac_no_dr
  6           from abc
  7          ) x
  8    on (a.account_class = x.account_class)
  9    when matched then update set a.ac_no_dr = x.ac_no_dr;

1 row merged.

结果：

SQL> select * From xyz;

ACCOUNT_NO ACCOUNT_CLASS A
---------- ------------- -
      1234          2003 Y

SQL>

最重要的是：您不需要过程或循环（效率低下），因为一切都可以用一个SQL语句完成。

如果-正如您所评论-必须是一个过程，那么也没问题：

create or replace procedure p_merge as
begin
  merge into xyz a
  using (select account_class,
                case when sysdate between start_date and end_date then 'Y'
                     else 'N'
                end ac_no_dr
         from abc
        ) x
  on (a.account_class = x.account_class)
  when matched then update set a.ac_no_dr = x.ac_no_dr;
end;
/

如何使用游标更新表

1 个答案: