Question

我为一个过程创建了一个Cursor。我正在尝试将标志应用于该游标中的记录。

Create or Replace Procedure Pledges 
(IDdonor In Int)
is 
Cursor Cur_Pledges is 
Select dd_pledge.iddonor, dd_status.idstatus from dd_donor
join dd_pledge on dd_donor.iddonor=dd_pledge.iddonor
join dd_status on dd_pledge.idstatus=dd_status.idstatus;
Type All_Pledges2 is record(iddonor dd_pledge.iddonor%type, idstatus dd_status.idstatus%type, flag Varchar2(10));
Begin
  For Rec_Pledges in Cur_Pledges LOOP
    if rec_pledges.idstatus = '10' THEN Flag := 'True';
      elsif rec_pledges.idstatus= '20' THEN Flag := 'False';
    End if;
  Insert Into All_Pledges
    Values(rec_pledges.idddonor, rec_pledges.idstatus, flag);
  End Loop;
End;

Answer 1

您错误地使用了类型记录变量，我已经进行了更改，请查看下面的内容，这将有效：

Create or Replace Procedure Pledges 
(IDdonor In Int)
is 
Cursor Cur_Pledges is 
Select dd_pledge.iddonor, dd_status.idstatus from dd_donor
join dd_pledge on dd_donor.iddonor=dd_pledge.iddonor
join dd_status on dd_pledge.idstatus=dd_status.idstatus;
Type All_Pledges2 is record(iddonor dd_pledge.iddonor%type, idstatus dd_status.idstatus%type, flag Varchar2(10));
-- new change below
allpledges2 All_Pledges2;
Begin
  For Rec_Pledges in Cur_Pledges LOOP
    if rec_pledges.idstatus = '10' THEN 
      allpledges2.Flag := 'True';
      elsif rec_pledges.idstatus= '20' THEN 
      allpledges2.Flag := 'False';
    End if;
  Insert Into All_Pledges
    Values(rec_pledges.iddonor, rec_pledges.idstatus, allpledges2.flag);
  End Loop;
End;

Answer 2

虽然您可以使用游标循环执行此操作，但您不应该这样做。通常，如果最小化上下文更改的数量并让SQL优化器完成它的工作，PL / SQL的性能最佳。此过程应包含单个insert语句：

CREATE OR REPLACE PROCEDURE pledges (iddonor IN INT) IS
BEGIN
   INSERT INTO all_pledges
      SELECT dd_pledge.iddonor,
             dd_status.idstatus,
             CASE dd_status.idstatus
                WHEN '10' THEN 'True'
                WHEN '20' THEN 'False'
             END
      FROM   dd_donor
             JOIN dd_pledge ON dd_donor.iddonor = dd_pledge.iddonor
             JOIN dd_status ON dd_pledge.idstatus = dd_status.idstatus;
END pledges;

值得注意的是，正如所写的那样，iddonor参数是多余的：因为你没有在代码中引用它，所以没有任何意义。

如果目标是简单地将结果返回给另一个程序，则根本不需要插入（使用表返回结果集在Oracle中不是一个好的模式）。处理它的最佳方法通常是打开引用游标并返回：

CREATE OR REPLACE PROCEDURE pledges (iddonor IN INT,
                                     all_pledges OUT SYS_REFCURSOR) IS
BEGIN
   OPEN all_pledges FOR
      SELECT dd_pledge.iddonor,
             dd_status.idstatus,
             CASE dd_status.idstatus
                WHEN '10' THEN 'True'
                WHEN '20' THEN 'False'
             END
      FROM   dd_donor
             JOIN dd_pledge ON dd_donor.iddonor = dd_pledge.iddonor
             JOIN dd_status ON dd_pledge.idstatus = dd_status.idstatus
      WHERE  dd_donor.iddonor = pledges.iddonor;
END pledges;

或者，您可以返回用户定义的类型或将结果写入全局临时表。

创建游标和过程

2 个答案: