PL SQL映射结果集为多个记录

Question

如果我们有3个表，例如A，B和C以及像

这样的游标

FOR i IN (
     SELECT * 
       FROM A 
       JOIN B ON(...)
       JOIN C ON(...)
) LOOP
--is there an easy way to map every row to 3 records(A%rowtype, B%rowtype and C%rowtype)?
END LOOP;

Answer 1

请注意，按ROWID提取记录的速度要快于索引。但是通过以下技巧，你将获得微小的性能损失（与简单的FOR LOOP相比），因为没有任何东西是免费的。

DECLARE
  l_rec_a table_A%ROWTYPE;
  l_rec_b table_B%ROWTYPE;
BEGIN

  FOR i IN (SELECT a.ROWID first
                 , b.ROWID second
                 FROM table_A AS a
                 JOIN table_B AS b on a.id = b.id)
  LOOP
    SELECT * INTO l_rec_a FROM table_A WHERE ROWID = i.first;
    SELECT * INTO l_rec_b FROM table_B WHERE ROWID = i.second;

   /* do something */

  END LOOP;

END;