嵌套SQL游标

Question

在我的产品表中，我有14种产品，在美国的每个州，每个产品都需要一行。 我正在尝试通过以下方法实现这一目标：

begin tran
declare @state varchar(2),
        @productId int

declare stateCursor CURSOR FOR
select distinct [State]
from lookUpAreaFactor

declare productCursor CURSOR FOR
select distinct productid 
from Product


open stateCursor
open productCursor
FETCH NEXT from stateCursor into @state
fetch next from productCursor into @productId
while @@FETCH_STATUS = 0
BEGIN

        while @@FETCH_STATUS = 0
        BEGIN
            insert into ProductToState (ProductID,[State]) values (@productId,@state)
            fetch next from productCursor into @productId
        END
    fetch next from stateCursor into @state
END

close stateCursor
close productCursor
select * from producttostate 
rollback

它在第一个产品问世之后就轰炸了-但它甚至没有为所有50个州插入一行。 我可以用另一双眼睛-我在做什么错了？

Answer 1

为什么将游标用于基于集合的操作？

我认为此查询可以满足您的需求：

insert into ProductToState(ProductID, [State])
    select ProductId, State
    from (select distinct [State] from lookUpAreaFactor) s cross join
         (select distinct ProductId from Product) p;

Answer 2

您需要使用游标吗？ 如果您不这样做，则可以通过简单的交叉连接来实现

INSERT INTO ProductToState 
        ( [STATE], productid )
SELECT DISTINCT  s.[State], p.productid
FROM products p CROSS JOIN lookUpAreaFactor s