How to get top 3 frequencies in MySQL?

Posted by Amenhotep on Stack Overflow See other posts from Stack Overflow or by Amenhotep
Published on 2010-03-16T21:03:55Z Indexed on 2010/03/16 22:11 UTC
Read the original article Hit count: 297

Filed under:

mysql-query

|

aggregate

|

frequency

|

mysql

|

sql

Hello,

In MySQL I have a table called "meanings" with three columns:

"person" (int),
"word" (byte, 16 possible values)
"meaning" (byte, 26 possible values).

A person assigns one or more meanings to each word:

person word meaning
-------------------
1      1    4
1      2    19
1      2    7 <-- second meaning for word 2
1      3    5
...
1      16   2

Then another person, and so on. There will be thousands of persons.

I need to find for each of the 16 words the top three meanings (with their frequencies). Something like:

word 1: meaning 5 (35% of people), meaning 19 (22% of people), meaning 2 (13% of people)

word 2: meaning 8 (57%), meaning 1 (18%), meaning 22 (7%)

...

Is it possible to solve this with a single MySQL query?

(If this problem is a classic one and has been answered elsewhere, I would appreciate if you could give me a link to the solution.)

Thank you very much,
ve

© Stack Overflow or respective owner

Related posts about mysql-query

MySQL query returns different set of results on two identical databases

as seen on Stack Overflow - Search for 'Stack Overflow'
I exported a live MySQL database (running mysql 5.0.45) to a local copy (running mysql 5.1.33) with no errors upon import. There is a view in the database, that when executed locally, returns a different set of data than when executed remotely. It's returning 32 results instead of 63. When I execute… >>> More
What's wrong with my MySql query ?!

as seen on Stack Overflow - Search for 'Stack Overflow'
This is a query I am doing with mysql using PHP This is the query line <?php $query = "SELECT * FROM node WHERE type = 'student_report' AND uid = '{$uid}' LIMIT 1 ORDER BY created DESC"; ?> I get the following error You have an error in your SQL syntax; check the manual that corresponds… >>> More
Optimizing the MySQL Query Cache

as seen on Internet.com - Search for 'Internet.com'
MySQL's query cache is an impressive piece of engineering if sometimes misunderstood. Keeping it optimized and used efficiently can make a big difference in the overall throughput of your application, so it's worth taking a look under the hood, understanding it, and then keeping it tuned optimally. >>> More
index help for a MySQL query using greater-than operator and ORDER BY

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a table with at least a couple million rows and a schema of all integers that looks roughly like this: start stop first_user_id second_user_id The rows get pulled using the following queries: SELECT * FROM tbl_name WHERE stop >= M AND first_user_id=N AND second_user_id=N… >>> More
mysql query using jdbc

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi all, I have the following table: Service_ID feedback 31 1 32 1 33 1 1 I have the sample code to find the sum: ResultSet res = st.executeQuery("SELECT Service_ID,SUM(consumer_feedback)… >>> More

Related posts about aggregate

Error in running script [closed]

as seen on Programmers - Search for 'Programmers'
I'm trying to run heathusf_v1.1.0.tar.gz found here I installed tcsh to make build_heathusf work. But, when I run ./build_heathusf, I get the following (I'm running that on a Fedora Linux system from Terminal): $ ./build_heathusf Compiling programs to build a library of image processing functions… >>> More
Semi-complex aggregate select statement confusion

as seen on Stack Overflow - Search for 'Stack Overflow'
Alright, this problem is a little complicated, so bear with me. I have a table full of data. One of the table columns is an EntryDate. There can be multiple entries per day. However, I want to select all rows that are the latest entry on their respective days, and I want to select all the columns… >>> More
Simple LINQ Aggregate Query

as seen on Stack Overflow - Search for 'Stack Overflow'
What is the vb.net equivalent of the following psuedo-code using LINQ? select min(credits) minCredits, max(credits) maxCredits, min(dollars) minDollars, max(dollars) maxDollars from players minCredits_lbl.Text = minCredits ... maxDollars_lbl.Text = maxDollars I have the following, but… >>> More
How to aggregate over few types with linq?

as seen on Stack Overflow - Search for 'Stack Overflow'
Can someone help me translate the following to one liner: Dim items As New List(Of Object) For Each c In ph.Contacts items.Add(New With {.Type = "Contact", .Id = c.ContactId, .Title = c.Title}) Next For Each c In ph.Persons items.Add(New With {.Type = "Person", .Id = c.PersonId, .Title =… >>> More
ORM Persistence by Reachability violates Aggregate Root Boundaries?

as seen on Stack Overflow - Search for 'Stack Overflow'
Most common ORMs implement persistence by reachability, either as the default object graph change tracking mechanism or an optional. Persistence by reachability means the ORM will check the aggregate roots object graph and determines wether any objects are (also indirectly) reachable that are not… >>> More