classement rang mysql 7

1CREATE TABLE person (id int, first_name varchar(20), age int, gender char(1));
2
3INSERT INTO person VALUES (1, 'Bob', 25, 'M');
4INSERT INTO person VALUES (2, 'Jane', 20, 'F');
5INSERT INTO person VALUES (3, 'Jack', 30, 'M');
6INSERT INTO person VALUES (4, 'Bill', 32, 'M');
7INSERT INTO person VALUES (5, 'Nick', 22, 'M');
8INSERT INTO person VALUES (6, 'Kathy', 18, 'F');
9INSERT INTO person VALUES (7, 'Steve', 36, 'M');
10INSERT INTO person VALUES (8, 'Anne', 25, 'F');

1Bill    32  M   4
2Bob     25  M   2
3Jack    30  M   3
4Nick    22  M   1
5Steve   36  M   5
6Anne    25  F   3
7Jane    20  F   2
8Kathy   18  F   1

1SELECT    a.first_name,
2      a.age,
3      a.gender,
4        count(b.age)+1 as rank
5FROM  person a left join person b on a.age>b.age and a.gender=b.gender 
6group by  a.first_name,
7      a.age,
8      a.gender