MySQL的分組

Question

我希望將我的數據按年齡和性別：像這樣的樣本數據：

Age: 1 
     Male: 2 
     Female: 3 
     Age 1 Total: 5 

Age: 2 
     Male: 6 
     Female: 3 
     Age 2 Total: 9 

我怎麼能集團根據年齡和數據統計在那個時代所有的男性和女性從MySQL數據庫？

Answer 1

Select age, gender, Count(*) cnt 
From your_table 
Group By age, gender 

將讓你

Age Gender cnt 
    1 Male  2 
    1 Female 3 
    2 Male  6 
    2 Female 9 

您應該能夠總結計數每個年齡在PHP之後。

Answer 2

SELECT 
    age, 
    SUM(CASE WHEN gender = 'male' THEN 1 ELSE 0 END) males, 
    SUM(CASE WHEN gender ='female' THEN 1 ELSE 0 END) females, 
    COUNT(*) total 
FROM yourtable 
GROUP BY age