条件程序 oracle Pl/sql

Question

我想创建一个具有以下条件的过程

$$
select 'Y'
     from dual
    where exists
             (select 'Y'
                from pa_expenditure_items_all paei, pa_expenditures_all pae
               where     paei.expenditure_id = pae.expenditure_id
                     and pae.incurred_by_person_id =&person_id
                     and paei.cost_distributed_flag = 'N')
$$

如果条件返回 Null 那么它应该显示一条错误消息，然后是一个错误。 对于错误消息，我正在使用 dbms_output.put_line，对于错误，我正在使用异常，那么任何人都可以帮助我解决这些问题

我正在尝试这些

 create or replace procedure validate_terminate
declare
l_yes out varchar2 (1);
null_found exception;
is
begin
   select 'Y'
     into l_yes
     from dual
    where exists
             (select 'Y'
                from pa_expenditure_items_all paei, pa_expenditures_all pae
               where     paei.expenditure_id = pae.expenditure_id
                     and pae.incurred_by_person_id =&person_id
                     and paei.cost_distributed_flag = 'N');

   if l_yes is null
   then
      dbms_output_put_line ('Condition is not met'); 
   raise null_found;
   end if;
   exception 
   when null_found then 
     dbms_output_put_line('CANNOT PROCESS TERMINATE');
end;

Answer 1

声明过程时使用IS而不是DECLARE - 不要同时使用两者。

您无需检查l_yes是否为 null - 如果您的 select 返回 0 行，它将自动引发NO_DATA_FOUND异常。 抓住那个。

您不需要第二次 select（来自双重）。 第一个 select 工作正常。

声明中的l_yes之后不要out 。 这只是l_yes varchar2(1); .

它是dbms_output.put_line 。

使用绑定变量:person_id而不是替换变量&person_id

set define off
create or replace procedure validate_terminate
is
   l_yes varchar2(1);
begin
   select 'Y'
     into l_yes
     from dual
    where exists
             (select 'Y'
                from pa_expenditure_items_all paei, pa_expenditures_all pae
               where     paei.expenditure_id = pae.expenditure_id
                     and pae.incurred_by_person_id = :person_id
                     and paei.cost_distributed_flag = 'N');

   exception 
   when NO_DATA_FOUND then
     dbms_output.put_line ('Condition is not met');  
     dbms_output.put_line('CANNOT PROCESS TERMINATE');
     raise;
end;
/

Answer 2

您的变量声明和异常处理不正确。

试试下面的代码：

create or replace procedure validate_terminate
declare
l_yes varchar2(1);
--null_found exception;
is
begin
   select 'Y'
     into l_yes
     from pa_expenditure_items_all paei, pa_expenditures_all pae
   where paei.expenditure_id = pae.expenditure_id
     and pae.incurred_by_person_id =&person_id
     and paei.cost_distributed_flag = 'N';
   exception 
   when no_data_found then 
     dbms_output_put_line ('Condition is not met'); 
     dbms_output_put_line('CANNOT PROCESS TERMINATE');
end;
/

干杯！！

Answer 3

PL/SQL 不是交互式编程语言。 是实现SQL及相关代码实现其他客户端调用的工具。 是那些处理用户输入和其他 UI 事物的客户端。

因此，编写程序的惯用方式是将 PERSON_ID 作为参数传递....

create or replace procedure validate_terminate
   (p_person_id in pa_expenditure_items_all.incurred_by_person_id%type ) 
is
  l_yes out varchar2 (1);
  null_found exception;
is
begin
   select 'Y'
   into l_yes
   from dual
   where exists
             (select 'Y'
                from pa_expenditure_items_all paei
                     ,pa_expenditures_all pae
               where paei.expenditure_id = pae.expenditure_id
                 and pae.incurred_by_person_id =p_person_id
                 and paei.cost_distributed_flag = 'N');

   if l_yes is null
   then
      dbms_output_put_line ('Condition is not met'); 
   raise null_found;
   end if;
exception 
   when null_found then 
     dbms_output_put_line('CANNOT PROCESS TERMINATE');
end;

然后你像这样调用这个过程（假设你想使用 SQL*Plus，正如你选择的符号所暗示的那样）：

exec validate_terminate(&person_id)

注意我假设 PERSON_ID 是数字； 如果它是一个字符串，你需要引用它。