Question

我的情景略有不同。我在存储过程中所做的是

创建临时表并使用“光标”

插入行

Create Table #_tempRawFeed
    (
    Code            Int Identity,
    RawFeed         VarChar(Max)
    )

使用游标

在临时表中插入数据

 Set @GetATM = Cursor Local Forward_Only Static For
    Select DeviceCode,ReceivedOn
    From RawStatusFeed
    Where C1BL=1 AND Processed=0
    Order By ReceivedOn Desc
Open @GetATM
Fetch Next
From @GetATM Into @ATM_ID,@Received_On
While @@FETCH_STATUS = 0
    Begin
        Set @Raw_Feed=@ATM_ID+' '+Convert(VarChar,@Received_On,121)+' '+'002333'+' '+@ATM_ID+' : Bills - Cassette Type 1 - LOW '
        Insert Into #_tempRawFeed(RawFeed) Values(@Raw_Feed)
        Fetch Next
        From @GetATM Into @ATM_ID,@Received_On
    End

现在必须使用另一个Cursor

处理Temp Table中的每一行

DECLARE @RawFeed    VarChar(Max)

DECLARE Push_Data CURSOR FORWARD_ONLY LOCAL STATIC
FOR SELECT RawFeed
FROM #_tempRawFeed

OPEN Push_Data
FETCH NEXT FROM Push_Data INTO @RawFeed

WHILE @@FETCH_STATUS = 0
BEGIN
    /* 
    What Should i write here to retrieve each row one at a time ??
    One Row should get stored in Variable..in next iteration previous value should get deleted.
    */
    FETCH NEXT FROM Push_Data INTO @RawFeed 
END
CLOSE Push_Data
DEALLOCATE Push_Data

Drop Table #_tempRawFeed

我应该在BEGIN中写一下每次检索一行？ One Row应该存储在Variable..in下一次迭代中，之前的值应该被删除。

Answer 1

关于你的上一个问题，如果你在最后一个光标中真正打算做的是将RawFeed列值连接成一个变量，则根本不需要游标。您可以使用以下内容（根据您的SQL小提琴代码改编）：

CREATE TABLE #_tempRawFeed
(
   Code            Int IDENTITY
   RawFeed         VarChar(MAX)
)

INSERT INTO #_tempRawFeed(RawFeed) VALUES('SAGAR')
INSERT INTO #_tempRawFeed(RawFeed) VALUES('Nikhil')
INSERT INTO #_tempRawFeed(RawFeed) VALUES('Deepali')

DECLARE @RawFeed    VarChar(MAX)

SELECT @RawFeed = COALESCE(@RawFeed + ', ', '') + ISNULL(RawFeed, '') 
FROM #_tempRawFeed

SELECT @RawFeed

DROP TABLE #_tempRawFeed

更多关于将不同的行值连接到一个字符串：Concatenate many rows into a single text string?

我很确定你也可以避免使用第一个游标。请避免使用游标，因为真的伤害了性能。使用基于集合的操作可以实现相同的结果。

使用游标处理存储过程中表中的每一行

1 个答案: