Question

我有一个表格，我想要选择最后10％的行，偏移10％（所以我想选择最后80-90％的数据）。

我写了以下查询

SELECT TOP 10 PERCENT
   [col1], [col2]
FROM [table]
ORDER BY [col1] DESC
OFFSET 10 ROWS

但是我收到以下错误：

第5行：'OFFSET'附近的语法不正确。

我做错了什么？我使用的Microsoft SQL Server 2012应与OFFSET

兼容

Answer 1

尝试这样的事情......

SELECT TOP (50) PERCENT *
FROM (
        SELECT TOP (20) PERCENT 
                      [col1]
                     ,[col2]
        FROM [table]
        ORDER BY [col1] DESC
     )T
ORDER BY [col1] ASC

Answer 2

对于您的错误消息，您的数据库是否设置为backwards compatibility mode？

offset表达式只允许您指定行号，而不是百分比。您可以选择80-90百分位数，如：

select  *
from    (
        select  100.0 * row_number() over (order by FirstName desc) /
                    count(*) over () as perc_pos
        from    YourTable
        ) as SubQueryAlias
where   80 <= perc_pos and perc_pos < 90

Answer 3

你可以使用一个简单的好旧而不是：

SELECT TOP 10 PERCENT [col1], [col2] 
FROM [table] 
WHERE [col1] NOT IN (
    SELECT TOP 10 PERCENT [col1]
    FROM [table]
    ORDER BY [col1] DESC
)
ORDER BY [col1] DESC

Answer 4

如果您正在寻找一种呈现方式，例如在网页上显示数据块。

尝试

    WITH Ordered AS
(
    SELECT *,
    ROW_NUMBER() OVER (ORDER BY ServerName) AS 'RowNumber'
    FROM systems
) 
SELECT *
FROM Ordered
WHERE RowNumber BETWEEN 11 AND 20

使用此代码，我可以为用户提供前10个，然后是第二个10（11-20），以此类推。

现在，请注意。如果您的数据频繁更改，则可能会受到影响，因为它将在完成查询时为您提供前10行（或50至60行）。

因此，如果添加了新数据，则会警告该列表。例如，如果您查看计算机列表，并且某人添加了一个名为“ AAA”的新服务器，并且您查看列表的中间位置，那么一个查询中的项目50可能是第二个查询中的项目49。（我希望我不要再对此感到困惑了。）

Answer 5

select top 1 *
from Employee
where empid in (
    select top 50 percent empid
    from employee
    order by empid
)
order by empid desc

Answer 6

declare @middle1 as int
set @middle1 = ((select COUNT(*) from [table] )+1)/2
declare @middle2 as int
set @middle2 = ((select COUNT(*) from [table] ))/2

select * from 
(select ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) as R, * from [table] where (select COUNT(*) from [table] ) % 2 = 0) T2
where  (T2.R - @middle2 = 0) or (T2.R- @middle1 = 0)
union
select * from 
(select ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) as R, * from [table] where (select COUNT(*) from [table] ) % 2 != 0) T2
where  T2.R - @middle1 = 0

在SQL Server中选择中间行

6 个答案: