Mysql - GROUP BY Avoid using tempoary

Posted by jwzk on Stack Overflow See other posts from Stack Overflow or by jwzk
Published on 2010-04-21T20:59:23Z Indexed on 2010/04/21 21:03 UTC
Read the original article Hit count: 170

Filed under:

mysql

|

mysql-query

The goal of this query is to get a total of unique records (by IP) per ref ID.

SELECT COUNT(DISTINCT ip), GROUP_CONCAT(ref.id)
FROM `sess` sess
JOIN `ref` USING(row_id)
WHERE sess.time BETWEEN '2010-04-21 00:00:00' AND '2010-04-21 23:59:59'
GROUP BY ref.id
ORDER BY sess.time DESC

The query works fine, but its using a temporary table. Any ideas?

© Stack Overflow or respective owner

Related posts about mysql

How to remove MySQL completely with config and library files on ubuntu 12.04 gnome 3.0

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried everything till now: sudo apt-get remove mysql-server mysql-client mysql-common sudo apt-get purge mysql-server mysql-client mysql-common sudo apt-get autoremove and even more commands... But whenever I am trying to locate mysql. I get a no. of files related to mysql command: shell>>… >>> More
mysql: Cannot load from mysql.proc. The table is probably corrupted

as seen on Server Fault - Search for 'Server Fault'
Mysql was started: /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 but when I'm trying to do something: ERROR 1548 (HY000) at line 1: Cannot… >>> More
Why is there a /etc/init.d/mysql file on this Slackware machine? How could it have gotten there?

as seen on Server Fault - Search for 'Server Fault'
A client of my IT-consulting service owns a web-development shop. He's been having problems with a Slackware 12.0 server running MySQL 5.0.67. The machine was set up by the client's sysadmin, who left on bad terms. My client no longer employs a sysadmin. As far as I can tell, the only copy of MySQL… >>> More
mysql: Bind on unix socket: Permission denied

as seen on Server Fault - Search for 'Server Fault'
Can't start mysql with: sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 120222 13:40:48 mysqld_safe Starting mysqld daemon with databases… >>> More
MySQL – Learning MySQL Online in 6 Hours – MySQL Fundamentals in 320 Minutes

as seen on SQL Authority - Search for 'SQL Authority'
MySQL is one of the most popular database language and I have been recently working with it a lot. Data have no barrier and every database have their own place. I have been working with MySQL for quite a while and just like SQL Server, I often find lots of people asking me if I have a tutorial which… >>> More

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
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
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