排序GROUP BY agregats

Question

想象一下這個表t1，

+----------+-------+--------+ 
| group_id | name | age | 
+----------+-------+--------+ 
| 1  | A1 | 1 | 
| 1  | A2 | 2 | 
| 1  | A3 | 3 | 
| 2  | B1 | 4 | 
+----------+-------+--------+ 

使用MySQL中下面的查詢，

SELECT group_id, name, COUNT(*) FROM t1 GROUP BY group_id 

我們得到，

+----------+-------+--------+----------+ 
| group_id | name | age | COUNT(*) | 
+----------+-------+--------+----------+ 
| 1  | A1 | 2 | 3  | 
| 2  | B1 | 4 | 1  | 
+----------+-------+--------+----------+ 

正如你可以在這裏看到，這是可能的值name = A1和age = 2不是來自同一記錄。

---

我的問題是，我怎麼可以控制單個結果形成name和age列顯示，所以內容是從一個記錄？有沒有辦法以某種方式對它們進行排序？例如按相反順序按年齡排序會給

+----------+-------+--------+----------+ 
| group_id | name | age | COUNT(*) | 
+----------+-------+--------+----------+ 
| 1  | A3 | 3 | 3  | 
| 2  | B1 | 4 | 1  | 
+----------+-------+--------+----------+ 

謝謝。

Answer 1

SELECT group_id, name, COUNT(*) 
FROM t1 
WHERE name IN ('xxx', 'yyy', ..., 'zzz') 
GROUP BY group_id 
SORT BY COUNT(*) 

Answer 2

我不知道完全控制，但你可以這樣做

SELECT student_name, MIN(test_score), MAX(test_score) 
     FROM student 
     GROUP BY student_name; 

Answer 3

我不知道你爲什麼說你的查詢工作。你也應該按名稱組...

SELECT group_id, name, COUNT(*) FROM t1 GROUP BY group_id, name 

如果你想只是其中之一，請嘗試：

SELECT group_id, MIN(name), COUNT(*) FROM t1 GROUP BY group_id