Question

can anyone please guide me with writing MySQL query for following scenario.

The data in table is like this,

Table Name: user

user_id     country     city            age
----------------------------------------------
1           India       Mumbai          22
2           India       Mumbai          22
3           India       Delhi           22
4           India       Delhi           23
5           India       Chennai         23
6           China       Beijing         20
7           China       Beijing         20
8           China       Shanghai        20
9           USA         New York        30
10          USA         New York        30
11          USA         New York        30
12          USA         Los Angeles     31
13          USA         Los Angeles     31
14          USA         Los Angeles     40

I want result to be like this which is basically sum of all users in particular country’s city having same age.

country     city            age     age_count
----------------------------------------------
India       Mumbai          22          2
India       Delhi           22          1
India       Delhi           23          1
India       Chennai         23          1
China       Beijing         20          2
China       Shanghai        20          1
USA         New York        30          3
USA         Los Angeles     31          2
USA         Los Angeles     40          1

Answer 1

Try this :;

SELECT country,
       city,
       age,
       count(user_id) AS age_count
FROM user
GROUP BY country,
         city,
         round(age)