Question

我有下面的代码，为什么我不想在@waitlistitmeID的临时表中获取最后一个值

10011没有被存储，虽然它的len是19并且应该被插入。在查询中需要帮助。

DECLARE @pos INT
    DECLARE @len INT
    DECLARE @value VARCHAR(MAX)
    declare @WaitlistItemID varchar(max)='10008,10009,10010,10011'
    declare @MovingWaitListItems table ( WaitlistItemID int, WaitlistItemGUID numeric(16,0))

    set @pos = 0
    set @len = 0

    while CHARINDEX(',', @WaitlistItemID, @pos+1)>0
    BEGIN
        set @len = CHARINDEX(',', @WaitlistItemID, @pos+1) - @pos
        set @value = SUBSTRING(@WaitlistItemID, @pos, @len)
        print @pos
        print @len
        print @value

        INSERT INTO @MovingWaitListItems 
        SELECT WaitlistItemID, WaitlistItemGUID
        FROM SXAAMWLWaitList    
        Where WaitlistItemID = @value
        select * from @MovingWaitListItems

        set @pos = CHARINDEX(',', @WaitlistItemID, @pos+@len) +1
        print @pos
    END

Answer 1

对于上述内容，我想使用xml节点方法，而不是使用substring()，CHARINDEX()函数

的循环

declare @WaitlistItemID varchar(max)='10008,10009,10010,10011'
declare @MovingWaitListItems table ( WaitlistItemID int, WaitlistItemGUID numeric(16,0))

;with  cte as
(
       select 
             a.value('.', 'varchar(max)') [WaitlistItemID] from 
       (
          select CAST('<m>'+REPLACE(@WaitlistItemID, ',', '</m><m>')+'</m>' as xml) as waitlist
       ) w cross apply waitlist.nodes ('/m') as split(a)
)

INSERT INTO @MovingWaitListItems
select S.WaitlistItemID, S.WaitlistItemGUID from SXAAMWLWaitList S
JOIN CTE C ON C.[WaitlistItemID] = S.WaitlistItemID

select * from @MovingWaitListItems

Answer 2

想象一下，如果你有一个带有单个元素10100的@WaitlistItemID，你也会跳过它，因为你的循环条件是假的。

while CHARINDEX(',', @WaitlistItemID, @pos+1)>0

最后一个元素也是如此。所以你必须在循环结束时添加另一个交互

while  ...
 begin
 end

set @len = LEN(@WaitlistItemID)

if @len > 0 
BEGIN    
    set @value = SUBSTRING(@WaitlistItemID, @pos, @len)

    INSERT INTO @MovingWaitListItems 
        SELECT WaitlistItemID, WaitlistItemGUID
        FROM SXAAMWLWaitList    
        Where WaitlistItemID = @value
END

SQL Server while循环不打印最后一个值

2 个答案: