获取最大字段值等于 x 的行

Question

Let's say that I have a table like this in a mysql database:

Id    number    version    date
1     123       1          2016-01-12
2     123       2          2016-01-13
3     124       1          2016-01-14
4     124       2          2016-01-15
5     124       3          2016-01-16
6     125       1          2016-01-17

I would like to get all the rows in my table where the value in the field version is the maximum value for each corresponding number . For example, I want to get this output:

Id    number    version    date
2     123       2          2016-01-13
5     124       3          2016-01-16
6     125       1          2016-01-17

I tried something like this:

SELECT * FROM myTable WHERE version = (SELECT MAX(version) FROM myTable)

But the above query returned empty.

Please help!

Answer 1

Use this

select * 
from myTable 
     natural join 
     (select max(version) as version, number from myTable group by number) as T;

Answer 2

You sould use in clause and group by

for original version

SELECT * FROM myTable 

WHERE (version, number) in 
      (SELECT MAX(version), number FROM myTable group by number)

for versione edited

SELECT * FROM myTable 
inner join myTable2 on myTable.id = myTable2.mytable_id
WHERE (version, number) in 
      (SELECT MAX(version), number FROM myTable group by number)

Answer 3

Here's a couple of options, and fiddles. These each select only rows that have a maximum version for their associated number .

(fiddle)

select * 
  from releases r1 
  where version = 
  (
    select max(version) 
    from releases 
    where number=r1.number
  );

(fiddle) Here is a (probably better) version:

select * from releases 
where (version, number) in (
  select max(version), number 
  from releases 
  group by number
);

Answer 4

SQLFIDDLE for this

http://sqlfiddle.com/#!9/a931fb/1

SELECT * FROM demo WHERE version = (SELECT MAX(version) FROM demo)

This is working well