SQLite和計數

Question

我有一個表命名爲「數字」與4列（ID，N1，N2，N3）這樣的多場頻：

id = 1,2 3, 4 


N1 = 22 , 14 , 13 , 15 

N2 = 13 , 11 , 80 , 11 

N3 = 11 , 22 , 47 , 23 

我能指望個體數的總頻率在這張桌子裏？ (11 = 3) ** (22=2)等。

對於一個欄我的查詢是：

"SELECT N1, COUNT(*) as Frequency FROM number GROUP BY n1 order by count(*) desc" 

感謝您的可能的幫助

Answer 1

試試這個：

SELECT t.num, COUNT(t.num) 
FROM (SELECT N1 AS num FROM number 
     UNION ALL 
     SELECT N2 AS num FROM number 
     UNION ALL 
     SELECT N3 AS num FROM number) AS t 
GROUP BY t.num 
ORDER BY COUNT(t.num) desc; 

fiddle demo

UNION operator