迭代計數和where子句

Question

我需要協助。 我有很多用戶其生日：

SELECT COUNT(or SUM) ()    FROM ()

WHERE () = ''  

AND TIMESTAMPDIFF(YEAR, date_of_birth, CURDATE())=18(age)

我必須通過僅更改where子句中的使用期限來多次計算計數，總和，平均值以及類似這些內容。 如何確保我不會浪費很多年運行查詢的時間？ 我必須從18歲轉到65歲：

SELECT COUNT(or SUM) () FROM ()

WHERE () = ''  AND () = ''

AND ()<'' 

AND TIMESTAMPDIFF(YEAR, date_of_birth, CURDATE())=**19,29,21 etc**.

I would like this columns results:

count()  18

count()  19 etc

or

sum () 18

sum() 19 etc 

確實非常感謝您。

Answer 1

返回TIMESTAMPDIFF的結果作為列，然后使用GROUP BY 。

SELECT TIMESTAMPDIFF(YEAR, date_of_birth, CURDATE()) AS age, COUNT(*)
FROM ...
WHERE ...
GROUP BY age