没有排序依据的MySQL最大计数

select age,
    count(*),
    (select max(c) from 
        (select count(*) as c from pacient where age between 20 and 40 group by age) as x) as t 
from pacient 
where age between 20 and 40 
group by age 
order by age;

SELECT A.age, A.total, MAX(A.total) as max_value FROM (
    SELECT age, count(*) AS total 
    FROM pacient
    WHERE age BETWEEN 20 AND 40 
    GROUP BY age ORDER BY age) as A
GROUP BY A.age, A.total

select 
      p.Age,
      count(*)  CountPerAge,
      max(ar.AllRecs) AllRecs
   from
      pacient p,
      ( select count(*) AllRecs 
           from pacient p2
           where p2.age between 20 and 40 ) ar
   where 
      p.age between 20 and 40
   group by
      p.age

CREATE VIEW subqueryView 
    SELECT age, count(*) AS total 
    FROM pacient
    WHERE age BETWEEN 20 AND 40 
    GROUP BY age ORDER BY age

SELECT A.age, A.total, MAX(A.total) as max_value FROM (SELECT FROM subqueryView) as A
GROUP BY A.age, A.total