Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

MySQL: Select rows with highest value in a column only

Posted on 2009-03-29
2
Medium Priority
?
1,254 Views
Last Modified: 2013-12-12
Hello,

I want to fetch rows with the highest value in a column.
With this table contents given:

ID --- VERSION --- text
1  --- 1              --- abc
1  --- 2              --- def
1  --- 3              --- ghj
2  --- 1              --- mno
3  --- 1              --- uvw
3  --- 2              --- xyz

I want a query that gives me

ID --- VERSION --- text
1  --- 3              --- ghj
2  --- 1              --- mno
3  --- 2              --- xyz

as result. I need a performant query, as this query will by executed quite often (possibly multiple times when visiting a page).

I startet experimenting with GROUP BY, but couldn't quite get to a working result.

I'd be glad if someone could help me on this one.
CREATE TABLE test(id INT UNSIGNED NOT NULL AUTO_INCREMENT, version SMALLINT NOT NULL DEFAULT 1, text TEXT, PRIMARY KEY(id, version));
 
INSERT INTO test(id, version, text) values(1, 1, 'abc'), (1, 2, 'def'), (1, 3, 'ghj'), (2, 1, 'mno'), (3, 1, 'uvw'), (3, 2, 'xyz');

Open in new window

0
Comment
Question by:Chakotay505
2 Comments
 
LVL 39

Accepted Solution

by:
Roger Baklund earned 2000 total points
ID: 24012595
Try this:
select test.* 
from test 
join (
  select id,max(version) as max_version 
  from test 
  group by id
) m on test.id=m.id and version=max_version;

Open in new window

0
 
LVL 3

Author Comment

by:Chakotay505
ID: 24012662
Thanks, works great.
0

Featured Post

Transaction-level recovery for Oracle database

Veeam Explore for Oracle delivers low RTOs and RPOs with agentless transaction log backup and transaction-level recovery of Oracle databases. You can restore the database to a precise point in time, even to a specific transaction.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

By, Vadim Tkachenko. In this article we’ll look at ClickHouse on its one year anniversary.
It’s a season to be thankful, and we’re thankful for users like you who engage on site, solve technology problems, and network with others in the industry. What tech are we most thankful for? Keep reading.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…
In this video, Percona Solutions Engineer Barrett Chambers discusses some of the basic syntax differences between MySQL and MongoDB. To learn more check out our webinar on MongoDB administration for MySQL DBA: https://www.percona.com/resources/we…
Suggested Courses

580 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question