計數用戶

Question

我用戶名的表，和球迷就像這樣：

Username, Fan 
Bob, Rita 
Bob, Sue 
Bob, Rita 
Sue, Bob 
Rita, Sue 
Rita, Bob 
Rita, Sue

我希望能夠進行計數，以便生成的表是這樣的：

Rita, Bob, 2 
Sue, Bob, 1 
Sue, Rita, 2 
Bob, Sue, 1 
Bob, Rita, 1

基本上，鮑勃已經扇了麗塔兩次，鮑勃已經扇了兩次蘇，鮑勃扇蘇等一次等。

任何想法是什麼mysql的聲明應該看起來像？

Answer 1

SELECT Username, Fan, count(*) as count 
FROM table_name 
GROUP By Username, Fan 

Answer 2

試試這個：

select Username, Fan, count(Fan) 
from your_table 
group by Username 
order by Username 

Answer 3

子選擇可能是你想要什麼

SELECT a.*, 
(SELECT COUNT(*) FROM tab AS b WHERE b.feld = a.feld) AS cnt 
FROM tab AS a 
WHERE ...