Question

这似乎很简单;我必须直接错过一些东西。

TestTable的的
Value1（int）
Value2（int）
Value3（int）
Value4（int）

插入TestTable 20,30,40,50中
值1 = 20
Value2 = 30
Value3 = 40
Value4 = 50

我有数字37.我想返回30和40（这两个数字之间有37个）。

使用TSQL的最有效方法是什么？

Answer 1

declare @TestTable table (Value1 int, Value2 int, Value3 int, Value4 int)
insert into @TestTable values (20, 30, 40, 50)

declare @Value int = 37

select
  case
    when @Value between Value1 and Value2 then Value1
    when @Value between Value2 and Value3 then Value2
    when @Value between Value3 and Value4 then Value3
    when @Value > Value4 then Value4
  end as Val1,   
  case
    when @Value < Value1 then Value1 
    when @Value between Value1 and Value2 then Value2
    when @Value between Value2 and Value3 then Value3
    when @Value between Value3 and Value4 then Value4
  end as Val2
from @TestTable

结果：

Val1        Val2
----------- -----------
30          40

Answer 2

SELECT TOP 1 [value] FROM TestTable WHERE [value] <= @number ORDER BY [value] DESC
UNION
SELECT TOP 1 [value] FROM TestTable WHERE [value] >= @number ORDER BY [value]

可选地

SELECT
  (SELECT TOP 1 [value] FROM TestTable WHERE [value] <= @number ORDER BY [value] DESC) AS [min],
  (SELECT TOP 1 [value] FROM TestTable WHERE [value] >= @number ORDER BY [value]) AS [max]

在[value]字段上设置索引并检查您是否需要>= / <=或>= / <个范围。

Answer 3

你用一个包含你想要找到的值的变量替换34，但我认为这可以得到你想要的。

select
(select top 1 * from TestTable
where value > 34
order by value),

(select top 1 * from TestTable
where value < 34
order by value desc)

TSQL - 查找数字列表中数字的位置的有效方法？

3 个答案: