As Cloud technologies come of age, business leaders grapple with the impact it has on their team's skills and the gap associated with the use of a cloud platform.
Join experts from 451 Research and Concerto Cloud Services on July 27th where we will examine fact and fiction.
Course Of The Month
10 days, 1 hour left to enrollBecome a Premium Member and unlock a new, free course in leading technologies each month.
Solved
MySQL - Select Max Unique Order By
Posted on 2007-12-06
I am trying to create a list of data where id is sorted highest to lowest, but where each name is unique.
For example:
name : id : text
aaaa : 11 : stuff
bbbb : 12 : more stuff
aaaa : 13 : other stuff
bbbb : 14 : more other stuff
Query should return only one name for it's highest id only so:
bbbb : 14 : more other stuff
aaaa : 13 : other stuff
Thanks for reading.
For example:
name : id : text
aaaa : 11 : stuff
bbbb : 12 : more stuff
aaaa : 13 : other stuff
bbbb : 14 : more other stuff
Query should return only one name for it's highest id only so:
bbbb : 14 : more other stuff
aaaa : 13 : other stuff
Thanks for reading.
SELECT name, MAX(id) AS id, text,
option
FROM dataset1
LEFT OUTER JOIN dataset2 ON name_fk = name
WHERE something!=1
GROUP BY name
ORDER BY id DESC
LIMIT 15;
[X]
Welcome to Experts Exchange
Add your voice to the tech community where 5M+ people just like you are talking about what matters.
- Help others & share knowledge
- Earn cash & points
- Learn & ask questions
3-
2
6 Comments
SELECT name, id, text,
option
FROM dataset1
LEFT OUTER JOIN dataset2 ON name_fk = name
WHERE something!=1
AND id = (SELECT MAX(ID) from dataset1 x where x.name = dataset1.name)
GROUP BY name
ORDER BY id DESC
LIMIT 15;
option
FROM dataset1
LEFT OUTER JOIN dataset2 ON name_fk = name
WHERE something!=1
AND id = (SELECT MAX(ID) from dataset1 x where x.name = dataset1.name)
GROUP BY name
ORDER BY id DESC
LIMIT 15;
Thanks, what about:
For example:
name : id : text : other :
aaaa : 11 : stuff : 5 :
bbbb : 12 : more stuff : 10 :
aaaa : 13 : other stuff : 12 :
bbbb : 14 : more other stuff : 1 :
Query should return only one name for it's highest other only so:
aaaa : 13 : other stuff : 12 :
bbbb : 12 : more stuff : 10 :
the field other is part of table dataset1
For example:
name : id : text : other :
aaaa : 11 : stuff : 5 :
bbbb : 12 : more stuff : 10 :
aaaa : 13 : other stuff : 12 :
bbbb : 14 : more other stuff : 1 :
Query should return only one name for it's highest other only so:
aaaa : 13 : other stuff : 12 :
bbbb : 12 : more stuff : 10 :
the field other is part of table dataset1
SELECT * FROM
(
SELECT name, id, text, other
FROM dataset1
LEFT OUTER JOIN dataset2 ON name_fk = name
WHERE something!=1
GROUP BY name
ORDER BY other desc
) AS Y
ORDER BY id DESC
LIMIT 15;
(
SELECT name, id, text, other
FROM dataset1
LEFT OUTER JOIN dataset2 ON name_fk = name
WHERE something!=1
GROUP BY name
ORDER BY other desc
) AS Y
ORDER BY id DESC
LIMIT 15;
![[Live Webinar] The Cloud Skills Gap](https://filedb.experts-exchange.com/files/public/2017/5/29/3249c5dc-214e-4f8f-afab-ef354630e19f.png)
i hope you always need only the highest id , what ever your field names are.
Most simple way seems like this.
Check this out...
select id, ename, text from Data a
where id in (select max(id) from Data group by ename)
order by id
Most simple way seems like this.
Check this out...
select id, ename, text from Data a
where id in (select max(id) from Data group by ename)
order by id
The problem with that imitchie is that it sorts the whole table, is there anyway to avoid sorting the whole table before selecting just the 15 records?
The problem is that the way you have prescribed the problem domain requires that you do sort everything, group them in a Particular order, then Sort them by a secondary order, however the limit 15 is applied to the Secondary order! You might just want to revisit what you can live with. Because there is an inherent dependancy in there.
Featured Post
Comparison of major players like AWS, Microsoft Azure, IBM Bluemix, and Google Cloud Platform
Question has a verified solution.
If you are experiencing a similar issue, please ask a related question
In part one, we reviewed the prerequisites required for installing SQL Server vNext.
In this part we will explore how to install Microsoft's SQL Server on Ubuntu 16.04.
It is possible to export the data of a SQL Table in SSMS and generate INSERT statements. It's neatly tucked away in the generate scripts option of a database.
The viewer will learn how to create and use a small PHP class to apply a watermark to an image. This video shows the viewer the setup for the PHP watermark as well as important coding language. Continue to Part 2 to learn the core code used in creat…
This tutorial will teach you the core code needed to finalize the addition of a watermark to your image. The viewer will use a small PHP class to learn and create a watermark.
Suggested Courses
Earn Certification
HTML5 Specialist - Certification
Free withPremium
Course of the Month10 days, 1 hour left to enroll
624 members asked questions and received personalized solutions in the past 7 days.
Join the community of 500,000 technology professionals and ask your questions.