SELECT
(
(SUM(id) * SUM(LOG (EPS)) - COUNT(*) * SUM(id * LOG (EPS))) / (SUM(id) * SUM(id) - COUNT(*) * SUM(id * id))
) AS a,from test
上面的SQL语句频繁的用到了相同的聚合函数有没有方法对它进行改进啊
(
(SUM(id) * SUM(LOG (EPS)) - COUNT(*) * SUM(id * LOG (EPS))) / (SUM(id) * SUM(id) - COUNT(*) * SUM(id * id))
) AS a,from test
上面的SQL语句频繁的用到了相同的聚合函数有没有方法对它进行改进啊
declare @a int
select @a=count(*) from test
再用@a来参与计算
(a*e-b*e)/(a*a-b*c) a
from
(select sum(id) a,count(*) b,sum(id*id) c,sum(log(eps)) d,SUM(id * LOG (EPS)) e from test) A
应该都差不多