的SQL Server 2008 R2：无法构造嵌套游标

Question

我有一个嵌套的游标的问题，无论它是一个无限循环或 错误是

消息16916，级别16，状态1，行1
一名称为'quantity_Cursor'的游标不存在。

这是我的最新版本的代码，导致此错误。

表看起来像这样

orders_ID orders_products_ID customers_Lastname quantity 
----------------------------------------------------------- 
1   1     Mark     1 
1   2     Mary     3 
2   3     Paul     2 
3   4     Linda     2 

所以我定义才达到一个分裂成表“订购货物”，其中所有的量是1

1   1     Mark     1 
1   2     Mary     1 
1   2     Mary     1 
1   2     Mary     1 
2   3     Paul     1 
2   3     Paul     1 
3   4     Linda     1 
3   4     Linda     1 

代码：

declare orders_Cursor Cursor for 
SELECT orders_ID, orders_products_ID, customers_Lastname FROM tblAlleWebshopBestellungen; 

open orders_Cursor; 
FETCH NEXT FROM orders_Cursor into @orders_ID_o, @orders_products_ID_o, @lastname_o; 



SET @Outer_loop = @@FETCH_STATUS 
WHILE @Outer_loop = 0 

BEGIN 
    DECLARE quantity_Cursor CURSOR FOR 
    SELECT products_quantity FROM tblAlleWebshopBestellungen where orders_products_ID= @orders_products_ID_o; 
    OPEN quantity_Cursor; 
    --Fetch the first record from quantity_Cursor 
    FETCH NEXT FROM quantity_Cursor into @quantity_q; 

    set @Counter_q=1 
    WHILE @Counter_q <= @quantity_q 

     BEGIN 

      --set @text_q= convert(nvarchar,@orders_products_ID_q)+' '+ @lastname_q +' '+ convert(nvarchar,@quantity_q) 
      PRINT convert(nvarchar,@orders_ID_o) +' '+ convert(nvarchar,@orders_products_ID_o)+' '+ @lastname_o +' ' +convert(nvarchar,@quantity_q) +' ' + convert(nvarchar,@counter_q) 
      set @Counter_q= @Counter_q+1 

      --Fetch next record from quantity_Cursor 
      FETCH NEXT FROM quantity_Cursor into @quantity_q; 
     END 
    CLOSE quantity_Cursor; 
    DEALLOCATE quantity_Cursor; 


end 
FETCH NEXT FROM orders_Cursor into @orders_ID_o, @orders_products_ID_o, @lastname_o; 

CLOSE orders_Cursor; 
DEALLOCATE orders_Cursor; 
GO 

我试了很多把Fetch Next from orders_Cursor，但我总是循环在第一顺序。所以我找不到这个Loop。

感谢您的帮助 迈克尔

Answer 1

不要使用光标这一点。简单JOIN有Tally表是足够的：

CREATE TABLE #tab(orders_ID INT, 
orders_products_ID INT, customers_Lastname VARCHAR(100), quantity INT); 

INSERT INTO #tab 
VALUES(1, 1, 'Mark', 1),(1, 2, 'Mary', 3),(2, 3, 'Paul', 2),(3, 4, 'Linda', 2); 


WITH tally(N) AS 
(
SELECT TOP 1000 ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) 
FROM sys.columns s1 
CROSS JOIN sys.columns s2 
) 
SELECT t.orders_ID, t.orders_products_ID , t.customers_Lastname , 1 
FROM #tab t 
JOIN tally t2 
    ON t2.N <= t.quantity 
ORDER BY t.orders_ID; 

LiveDemo

编辑：

帐簿桌 - 像任何其它表，但具有的单个列 连续数字，值startin g从1（或0）到一些N（int） 数字。

当然你可以使用，而不是使用many methods