用于数据操作任务的光标与基于集合的解决方案

Question

我正在阅读考试 70-461 Querying SQL Server 2012 的培训工具包。

第 604 页给出了一个示例，我正在对其进行测试，但它不起作用...有什么建议吗？

示例：

IF OBJECT_ID(N'dbo.GetNums', N'IF') IS NOT NULL DROP FUNCTION  dbo.GetNums;
GO

CREATE FUNCTION dbo.GetNums (@low as bigint, @high as bigint) RETURNS TABLE
AS
RETURN
WITH
    L0 as (SELECT c from (VALUES(1), (1)) as D(c)),
    L1 as (SELECT 1 as c FROM L0 as A CROSS JOIN L0 AS B),
    L2 as (SELECT 1 as c FROM L1 as A CROSS JOIN L1 AS B),
    L3 as (SELECT 1 as c FROM L2 as A CROSS JOIN L2 AS B),
    L4 as (SELECT 1 as c FROM L3 as A CROSS JOIN L3 AS B),
    L5 as (SELECT 1 as c FROM L4 as A CROSS JOIN L4 AS B),
    Nums as (SELECT ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) as rownum
            FROM L5)
SELECT @low + rownum - 1 as n
FROM Nums
ORDER BY rownum
OFFSET 0 ROWS 
FETCH FIRST @high - @low + 1 ROWS ONLY;
GO

错误信息：

消息 102，级别 15，状态 1，过程 GetNums，第 17 行
“OFFSET”附近的语法不正确。
消息 153，级别 15，状态 2，过程 GetNums，第 18 行
FETCH 语句中选项 FIRST 的使用无效。

Answer 1

上面的代码在 SQL Server 2008 R2 中运行时会产生错误消息，但在 SQL Server 2012 中运行成功。

OFFSET 和 FETCH 是 new features in 2012。