在mysql查詢中對數據進行分組或數據透視，使行成爲列

Question

我只是遇到了麻煩，無法對我需要的查詢進行分類。我有這樣

colDist  colGender   attnedancePrcnt 
Place-1  Male     2.5 % 
Place-1  Female    1.5% 
Place-2  Male     3.5% 
Place-2  Female    2.1% 

的情景現在我需要在mysql中查詢到有這樣

colDist  colMale   colFemale 
Place-1  2.5%    1.5 % 
Place-2  3.5%    2.1 % 

數據這有點組由coldDist但我只是面臨的麻煩，使colMale並從第一個數據集colfemale到第二個。

高級謝謝。

這種方法.....

select colDist, if(colGender='Male',colGender,null) as colMale , 
     if(colGender='Female',colGender,null) as colFemale 
from tablename 

給了我這樣的

colDist  colMale   colFemale   attnedancePrcnt 
Place-1  Male    NULL     2.5 
Place-1  NULL    Female    1.5 
Place-2  Male    NULL     3.5 
Place-2  NULL    Female    2.1 

的結果，但我又需要他們這樣的：

colDist  colMale   colFemale 
Place-1  2.5%    1.5 % 
Place-2  3.5%    2.1 % 

那麼怎麼可以根據需要對數據進行分組或轉儲？

謝謝。

Answer 1

SELECT 
    t1.colDist, 
    t1.attnedancePrcnt AS colMale, 
    t2.attnedancePrcnt AS colFemale 
FROM 
    tablename AS t1 
INNER JOIN tablename AS t2 ON t1.colDist = t2.colDist 
AND t1.colGender != t2.colGender 
WHERE 
    t1.colGender = 'Male' 

另外值得一提的是，「attnedance」應拼寫「出勤」。

Answer 2

檢查是否符合您的要求它的工作原理：

select colDist, if(colGender='Male',colGender,null) as colMale , 
     if(colGender='Female',colGender,null) as colFemale 
from tablename