SQL-经常出现的值

Question

I need a SQL where I get the id that's appears many more than the other ... But I need the id and not the count how often it founded the id ...

post    | id 
==============
hello   | 2
guys    | 1
how     | 2
are     | 2

It should give me "2" back.

Thanks for your help.

Answer 1

SELECT COUNT(*) AS cnt, id
FROM <table>
GROUP BY id
ORDER BY cnt DESC
LIMIT 1

Answer 2

what you're looking for is called the MODE, i have done a similar thing Is there a simpler way to find MODE(S) of some values in MySQL

for cases where there is more than 1 mode (for example, id 2 occurs 3 times and id 1 also occurs 3 times) ( sqlFiddle ) you can use one of the queries below

this one will return id 1 and 2 as a comma separated list (you have to replace yourTable with your actual table name of course)

SELECT GROUP_CONCAT(CASE WHEN occurs=@maxoccurs THEN value ELSE NULL END) as modes 
FROM 
    (SELECT value,occurs,@maxoccurs:=GREATEST(@maxoccurs,occurs) as maxoccurs
     FROM (SELECT id as value,count(*) as occurs
           FROM yourTable
           GROUP BY id)T1,(SELECT @maxoccurs:=0)mo
    )T2;

this one will return id 1 and 2 as 2 separate rows

SELECT value as id FROM  
  (SELECT value,occurs,@maxoccurs as maxoccurs
  FROM 
    (SELECT value,occurs,@maxoccurs:=GREATEST(@maxoccurs,occurs) as maxoccurs
     FROM (SELECT id as value,count(*) as occurs
           FROM yourTable
           GROUP BY id)T1,(SELECT @maxoccurs:=0)mo
     )T2
  )T3
WHERE occurs = maxoccurs