Is there any way to modify a column before it is ordered in MySQL?

Posted by George Edison on Stack Overflow See other posts from Stack Overflow or by George Edison
Published on 2010-03-19T23:59:03Z Indexed on 2010/03/20 0:01 UTC
Read the original article Hit count: 316

Filed under:

mysql

|

convert

|

currency

|

string

I have a table with a field value which is a varchar(255). The contents of the field can be quite varied:

$1.20
$2994
$56 + tax (This one can be ignored or truncated to $56 if necessary)

I have a query constructed:

SELECT value FROM unnamed_table ORDER BY value

However, this of course uses ASCII string comparison to order the results and does not use any numerical type of comparison.

Is there a way to truly order by value without changing the field type to DECIMAL or something else? In other words, can the value field be modified ('$' removed, value converted to decimal) on the fly before the results are sorted?

© 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
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
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 – 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 convert

Monitoring SQL Server Agent job run times

as seen on SQL Blogcasts - Search for 'SQL Blogcasts'
Introduction A few months back, I was asked how long a particular nightly process took to run. It was a super question and the one thing that struck me was that there were a plethora of factors affecting the processing time. This said, I developed a query to ascertain process run times, the… >>> More
Convert Dynamic to Type and convert Type to Dynamic

as seen on Geeks with Blogs - Search for 'Geeks with Blogs'
public static class DynamicExtensions { public static T FromDynamic<T>(this IDictionary<string, object> dictionary) { var bindings = new List<MemberBinding>(); foreach (var sourceProperty in typeof(T).GetProperties().Where(x => x… >>> More
Need help in filtering the data with various condition and filling in scroll window GP

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi all, I am filtering the data and displaying in scroll window. There are many combination to display this data by customer id, customer id and itemnumber, customer id, itemnumber, work and history condition. And from date and To date condition. My query is when I am selecting the customer id and… >>> More
Convert and convert back datetime in Django

as seen on Stack Overflow - Search for 'Stack Overflow'
I am parsing feeds using feedparser and I am trying to store updated or updated_parsed attributes of feeds in Django db. But it shows an error as [u'Enter a valid date/time in YYYY-MM-DD HH:MM[:ss[.uuuuuu]] format.'] Please tell me how to convert updated and updated_parsed such that it can be stored… >>> More
Redaction in AutoVue

as seen on Oracle Blogs - Search for 'Oracle Blogs'
As the trend to digitize all paper assets continues, so does the push to digitize all the processes around these assets. One such process is redaction - removing sensitive or classified information from documents. While for some this may conjure up thoughts of old CIA documents filled with nothing… >>> More