返回Oracle引用游标并附加多个结果

Question

我有这个问题,我希望有人知道答案.我有一个oracle存储过程,它接受客户ID并返回ref_cursor中的所有客户订单.过度简化它,这就是我所拥有的:

Orders
- orderId
- siteID

Customers
- siteID
- Name

GetOrder(siteID, outCursor) /* returns all orders for a customer */

现在,我需要编写另一个采用客户名称并执行LIKE查询以获取所有custId的过程,然后我需要重用GetOrder方法来返回找到的custIds的所有订单,如下所示:

   PROCEDURE GetOrderbyCustName(
      p_name       IN        VARCHAR2,
      curReturn    OUT       sys_refcursor
   )
   IS
      siteid    number;
   BEGIN
      FOR rec in SELECT site_id FROM customers WHERE name LIKE p_name
      LOOP 
      -- This will replace curReturn in each iteration
      -- how do I append instead?
        GetOrder(rec.site_id,
                   curReturn
                  );
      END LOOP;
   END GetOrderbyCustName;

我的问题是,如何在每次迭代中将GetOrder的返回附加到curReturn？正如它现在所写的那样,它会在循环的每个循环中覆盖它.谢谢!!

Answer 1

你不能这样做 - 游标不能被追加或合并.只需这样做:

PROCEDURE GetOrderbyCustName(
   p_name       IN        VARCHAR2,
   curReturn    OUT       sys_refcursor
)
IS
BEGIN
   OPEN curReturn FOR 
      SELECT o.orderID, o.siteID
      FROM Orders o
      JOIN Customers c ON c.siteID = o.siteID
      WHERE c.name LIKE p_name;
END GetOrderbyCustName;

Answer 2

如果查询很简单,我会说托尼的回答.这不仅简单,而且可能比为每个siteID执行一个查询更好.

如果它相当复杂,那么重用GetOrder过程可能需要额外的努力,因此您只需要维护一个查询.

为此,您需要在循环的每次迭代中实际从refcursor中获取数据,并将其放入其他一些数据结构中.

如果对接口有意义,一个选项是将GetOrderbyCustName更改为将PL/SQL索引表作为其输出参数而不是refcursor.通过循环在每次迭代时附加到该表.

如果确实需要返回refcursor,则可以使用嵌套表类型,然后返回查询该嵌套表的游标.像这样的东西(没有经过测试的代码):

CREATE TYPE number_table_type AS TABLE OF NUMBER;

PROCEDURE GetOrderbyCustName(
      p_name       IN        VARCHAR2,
      curReturn    OUT       sys_refcursor
   )
   IS
      cursor_source_table  number_table_type := number_table_type();
      single_site_cursor  sys_refcursor;
      orderID  NUMBER;
   BEGIN
      FOR rec in SELECT site_id FROM customers WHERE name LIKE p_name
      LOOP 
      -- This will replace curReturn in each iteration
      -- how do I append instead?
        GetOrder(rec.site_id,
                   single_site_cursor
                  );

        -- Fetch all rows from the refcursor and append them to the nested table in memory
        LOOP
          FETCH single_site_cursor INTO orderID;
          EXIT WHEN single_site_cursor%NOTFOUND;
          cursor_source_table.extend();
          cursor_source_table( cursor_source_table.COUNT+1) := orderID;
        END LOOP;
      END LOOP;

      OPEN curReturn FOR
        SELECT * FROM TABLE( cursor_source_table );

   END GetOrderbyCustName;