Question

我有一个处理数千行的SQL Server查询。但是脚本运行正常，但是我只需要在一个select语句中应用一个条件，但不会影响其余的结果。

Select
    Count ([key]) as KEYCOUNT, 
    Round (AVG ([AGE]),2) as AGE, 
    Round (AVG ([LENGTH]),2) as Length_X,
    Round (AVG ([Duration]),2) as DUR_Y,
from 
    [dbo].[XYZ]
where 
    [FLAG] = 1  and STAT = 3

我需要影响的选择是Round (AVG ([LENGTH]),2) as Length_X，我需要将其计算为仅大于0的长度的平均值，基本上不包括所有0（零）

非常感谢

干杯

Answer 1

您可以使用case表达式作为AVG函数的参数：

Round(AVG(case when [LENGTH] > 0 then [LENGTH] end), 2) as Length_X,

这样，AVG将忽略所有0值，而查询中的所有其他表达式都不会受到影响。

Answer 2

我需要计算的是只有那些大于0的长度的平均值，基本上不包括所有0（零）

如果需要，这是正和（长度）/总和（情况下长度为0然后0否则1结束）和适当的铸造。例如。

set nocount on; 
with cte as (select * from (values  (0), (1), (2), (1), (0), (0)) as l(length))
select avg(cast(length as float)) as avg1, 
sum(cast(length as float)) / sum(case length when 0 then 0 else 1 end) as avg2 
from cte; 

with cte as (select * from (values  (1), (2), (1) ) as l(length))
select avg(cast(length as float)) as avg1, 
sum(cast(length as float)) / sum(case length when 0 then 0 else 1 end) as avg2 
from cte;

注意案件情况。我用＆＃34;不是零＆＃34;，你说＆＃34;大于零＆＃34;。你选。

选择查询中的SQL排除

2 个答案: