解决游标问题

Question

我有个问题。我正在使用游标。每次获取最后的记录并打印其数据后，光标都会打印一条附加行。要理解我的意思，请考虑以下示例示例：我只想打印有关10个客户的信息。

USE Northwind
GO

DECLARE myCursor CURSOR 
FOR SELECT TOP(10) ContactName FROM Customers
DECLARE @RowNo int,@ContactName nvarchar(30)
SET @RowNo=1
OPEN myCursor
FETCH NEXT FROM myCursor INTO @ContactName
PRINT  LEFT(CAST(@rowNo as varchar) + '      ',6)+'  '+ @ContactName
SET @RowNo=@RowNo+1
SET @ContactName=''
WHILE @@FETCH_STATUS=0
  BEGIN
        FETCH NEXT FROM myCursor INTO @ContactName
        PRINT + LEFT(CAST(@rowNo as varchar) + '      ',6)+'  '+ @ContactName
        SET @RowNo=@RowNo+1
        SET @ContactName=''
  END
CLOSE myCursor
DEALLOCATE myCursor

现在看一下输出：

1       Maria Anders
2       Ana Trujillo
3       Antonio Moreno
4       Thomas Hardy
5       Christina Berglund
6       Hanna Moos
7       Frédérique Citeaux
8       Martín Sommer
9       Laurence Lebihan
10      Elizabeth Lincoln
11      

行号11也已打印。这是游标中的问题还是总是发生？有什么办法不打印此附加数据？谢谢（我使用sql erver 2008）

Answer 1

要么...

FETCH NEXT FROM myCursor INTO @ContactName
WHILE @@FETCH_STATUS = 0
BEGIN
    -- do stuff

    FETCH NEXT FROM myCursor INTO @ContactName
END

要么...

WHILE @@FETCH_STATUS = 0
BEGIN
    FETCH NEXT FROM myCursor INTO @ContactName
    IF @@FETCH_STATUS = 0
    BEGIN
        -- do stuff
    END
END

要么...

WHILE (1 = 1)
BEGIN
    FETCH NEXT FROM myCursor INTO @ContactName
    IF @@FETCH_STATUS <> 0
        BREAK

    -- do stuff
END