Question

我有一个看起来像这样的表：

Customer ID, MDN, Plan, StartDate, EndDate, Term, SMS Usage, Voice Usage

按使用顺序按升序或降序排序

我想删除所有记录的前5％，而最后50％留下剩下的90％的客户

Answer 1

SELECT TOP 5 PERCENT CustomerID
INTO #TopPct
FROM YourTable
ORDER BY SMSUsage;

SELECT TOP 5 PERCENT CustomerID
INTO #BottomPct
FROM YourTable
ORDER BY SMSUsage DESC;

DELETE FROM YourTable
WHERE CustomerID IN (
  SELECT CustomerID FROM #TopPct
  UNION
  SELECT CustomerID FROM #BottomPct
);

前两个查询正在收集记录的最高和最低百分比。最后一个查询使用（#TopPct和#BottomPct）中找到的记录来选择要删除的记录。

Answer 2

;WITH x AS
(
    SELECT CustomerID FROM 
    (
      SELECT TOP 5 PERCENT CustomerID FROM dbo.table 
      ORDER BY [SMS Usage]
    ) AS lowest
    UNION ALL
    SELECT CustomerID FROM
    (
      SELECT TOP 5 PERCENT CustomerID FROM dbo.table
      ORDER BY [SMS Usage] DESC
    ) AS highest
)
-- DELETE t FROM dbo.table AS t INNER JOIN x ON t.CustomerID = x.CustomerID;
SELECT CustomerID FROM t;

如果您对查询返回正确的行感到满意，则可以取消注释DELETE并注释或删除最后一行。

Answer 3

您可以使用ntile。

;with C as
(
  select ntile(20) over(order by SMSUsage) as nt
  from YourTable       
)      
delete from C
where nt in (1,20)

试试SE-Data

删除所有记录的前5％和后5％

3 个答案: