Question

我有两个数据库表（account和account1）。我想输入一个帐号，首先检查是否帐号是否在帐号表中。如果不在帐号表中，则引发异常并检查account1表。代码适用于此。但是，如果我想显示错误消息，如果在account1表中也找不到该帐号，那我该怎么办。这是我的部分代码-

BEGIN
begin
select Balance,Cid
    into cur_balance,cl_id
    from Account 
    where Accno = x;
    select max(Tid) into id from(select Tid from trnsaction union select Tid from trnsaction1);
    id:=id+1;
    ac_branch := 'mirpur';
exception
    when no_data_found then
    select Balance,Cid
    into cur_balance,cl_id
    from account1
    where accno = x;

    select max(Tid) into id from(select Tid from trnsaction union select Tid from trnsaction1);
    id:=id+1;

    ac_branch := 'gulshan';         

end;

Answer 1

您可以使用

raise_application_error(-20001,'None of the tables contain this account !');   或

dbms_output.put_line('None of the tables contain this account !');

在Account表的最后一个引发的异常语句中：

DECLARE
  cur_balance  Account.Balance%type;
  cl_id        Account.Cid%type;
  id           trnsaction.Tid%type;
BEGIN
  begin
        select Balance, Cid
          into cur_balance, cl_id
          from Account
         where Accno = x;

        ac_branch := 'mirpur';
    exception
      when no_data_found then
        select Balance, Cid
          into cur_balance, cl_id
          from Account1
         where accno = x;

      ac_branch := 'gulshan'; 

        exception
          when no_data_found then 
            raise_application_error(-20001,'None of the tables contain this account !');           
  end;     

  begin
      select max(Tid)
        into id
        from (select Tid
                from trnsaction
              union
              select Tid from trnsaction1);
      id := id + 1;

     exception
       when no_data_found then null;           
  end;    
END;

Account与Account1的列类型以及trnsaction1与trnsaction的表的列类型被认为相对相同。

如果您更喜欢使用dbms_output.put_line，请在其前发出命令set serveroutput on。

顺便说一句，无需重复其他与我们感兴趣的查询无关的查询。

Answer 2

union all和row_number为什么不显示？

begin
Select Balance,Cid, branch
into cur_balance,cl_id, ac_branch
from
(Select Balance,Cid, branch
       row_number() 
       Over (order by seq) as rn
From   
(select Balance,Cid, 1 as seq, 'mirpur' as branch
    from Account 
    where Accno = x
Union all
select Balance,Cid, 2 as seq, 'gulshan' as branch
    from account1
    where accno = x))
Where rn = 1;
    select max(Tid) into id from(select Tid from trnsaction union select Tid from trnsaction1);
    id:=id+1;
exception
    when no_data_found then
    Null; -- or dbms_output.put_line('acct not found');
end;
/

干杯！

oracle中的No_Data_found异常

2 个答案: