如何返回最接近零的值

Question

我得到了一个包含正数和负数的数字列的表格。如何找到 det 编号最接近于零的记录？

这个查询

SELECT MIN(ABS(dNumber))
FROM myTable

返回 det 最小绝对值。但是我希望返回签名值。

所以如果 myTable 包含 2 条记录；第一个dNumber = 2000，第二个dNumber = -1000，我希望查询返回-1000，而不是1000。

编辑：忘了提到这必须在聚合函数中作为其与 GROUP BY 查询的一部分

SELECT Key1, Key2, 
   SUM(CASE WHEN /*condition1*/ THEN dNumber ELSE NULL END) AS 'Value1',
   SUM(CASE WHEN /*condition2*/ THEN dNumber ELSE NULL END) AS 'Value2',
   MIN(ABS(dNumber)...) AS 'ClosestToZeroAndSigned'
FROM myTable
/*joins*/
WHERE /*conditions*/
GROUP BY Key1, Key2

Answer 1

一、单机查询

SELECT top 1 dNumber
FROM myTable
order by ABS(dNumber)

二、使用 group by 的较大查询的一部分

;with cte as
(
  SELECT Key1, Key2,
   SUM(CASE WHEN /*condition1*/ THEN dNumber ELSE NULL END) AS 'Value1',
   SUM(CASE WHEN /*condition2*/ THEN dNumber ELSE NULL END) AS 'Value2',
   -- max negative value
   max(case when dNumber <= 0 then dNumber else null end) as Negative,
   -- min positive value
   min(case when dNumber  > 0 then dNumber else null end) as Positive
  FROM myTable
  /*joins*/
  WHERE /*conditions*/
  GROUP BY Key1, Key2
)
select 
    Key1, Key2, Value1, Value2
    Negative, Positive,
    case when (abs(Negative) < Positive or Positive is null) then Negative else Positive end as 'ClosestToZeroAndSigned' 
from cte