如何計算分數超過90 SQL

Question

我想在90算分數，但這個結束了。如果我的數據是

100 
45 
90 
100 

它應該顯示3總行

select g.score as score 
     ,count(case when g.score>=90 then 1 else 0 end) over() as passed 
from grades g 

計數，而是它顯示4

Answer 1

你要麼刪除ELSE一部分，所以默認爲NULL和COUNT犯規次數NULL

select g.score as score 
     ,count(case when g.score>=90 then 1 end) over() as passed 
from grades g 

或更改COUNT爲SUM

select g.score as score 
     ,SUM(case when g.score>=90 then 1 else 0 end) over() as passed 
from grades g 

Answer 2

只需在SUM編輯COUNT。 COUNT計數非空值，所以它甚至計數0; SUM只會'計數'非零值