使 PL/SQL 存储过程在发生异常时回滚所有更改? [英] Make a PL/SQL stored procedure roll back all changes when an exception occurs?

问题描述

我有一个程序可以对不同的表进行多次更新.如果过程中的任何地方发生任何错误，我希望所有更改都回滚.因此我使用了这种结构:

I have a procedure that makes a number of updates to different tables. I want all of the changes to be rolled back should any error occur anywhere in the procedure. Therefore I utilized this structure:

CREATE PROCEDURE foo (x NUMBER) IS
BEGIN
  -- Do some inserts here.
  INSERT INTO bar VALUES (x);
  -- Sometimes there might be an error.
  IF x = 3 THEN
    RAISE_APPLICATION_ERROR(-20000, 'Wooops...');
  END IF;
EXCEPTION
  WHEN OTHERS THEN
    --Rollback all the changes and then raise the error again.
    ROLLBACK;
    RAISE;
END foo;

问题是这会回滚自上次提交以来所做的一切，而不仅仅是程序所做的更改.例如，这将插入 4 和 5，但会回滚 1 和 2:

The problem is that this rolls back everything that has been done since the last commit, not just the changes made by the procedure. For instance, this will insert 4 and 5, but 1 and 2 will be rolled back:

BEGIN
  FOR x IN 1..5 LOOP
    BEGIN
      foo(x);
    EXCEPTION
      WHEN OTHERS THEN
        NULL;
    END;
  END LOOP;
END;

我怎样才能让过程只回滚过程在这个调用期间所做的更改?我想我应该以某种方式使用事务，但我不确定如何设置.

How can I make the procedure roll back only the changes the procedure did during this call? I guess I should use transactions somehow, but I am not sure how to set it up.

请注意，我想在该过程的代码中修复此问题，而不是在调用它的代码中.

Please note that I want to fix this in the code for the procedure, and not in the code that calls it.

推荐答案

在 Oracle 中，您可以使用 SAVEPOINTS.应该是这样的:

In Oracle you can use SAVEPOINTS. It would be this:

CREATE PROCEDURE foo (x NUMBER) IS
BEGIN
  SAVEPOINT update_bar;

  -- Do some inserts here.
  INSERT INTO bar VALUES (x);
  -- Sometimes there might be an error.
  IF x = 3 THEN
    RAISE_APPLICATION_ERROR(-20000, 'Wooops...');
  END IF;
EXCEPTION
  WHEN OTHERS THEN
    -- Rollback everything which was made after `SAVEPOINT update_bar`
    ROLLBACK TO update_bar;
    RAISE;
END foo;

这篇关于使 PL/SQL 存储过程在发生异常时回滚所有更改?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！