Hey Texans!

This Sunday (3/9) Sun will be hosting an event at La Zona Rosa in Austin and has invited MySQL'ers and community members. Music will be from the Smithereens and Seven Mary Three. And Zack Urlocker will be in attendance.

We up in Dallas are trying to get a group to head South and hope to see you there.

If you are in the Austin area or can get there, this is a great opportunity to socialize.

Recently, I noticed a post on Planet MySQL expressing distaste for surrogate keys. Ever since reading it the topic has been bugging me so I thought I would finally break out a defense for surrogate keys.

Really, it comes down to the right tool for the right job. Like The Force, they can be used for both good and evil. The fact is that a surrogate key can be wildly useful and efficient if used in the right context. For instance, this blog uses surrogate keys here and there. I'll be honest, in some cases it may help and hinder. For instance, to maintain uniqueness, my BlogPosts table has an auto incremented primary key. To me, this makes sense. Yes, I …

Sometimes, the easy solution is not the best one. I saw this problem happening several times. The query returns duplicates, and the first reaction of the developer is to fix it with DISTINCT.

Let's look at an example. Given the data below:

select * from  people;
+-----------+-------+
| person_id | name  |
+-----------+-------+
|         1 | Joe   |
|         2 | Mary  |
|         3 | Frank |
+-----------+-------+
3 rows in set (0.00 sec)

select * from  projects;
+------------+-------------+-----------+
| project_id | descr       | person_id |
+------------+-------------+-----------+
|          1 | Joe First   |         1 |
|          2 | Joe second  |         1 |
|          3 | Mary First  |         2 |
|          4 | Mary second |         2 |
|          5 | Frank first |         3 |
+------------+-------------+-----------+
5 …

Attention MySQL certification candidates and those of you have earned your certifications: Please let us know if you have a new address or email.

First: This keeps us from sending your certificates to your old address. Tracking down your certification package can be very expensive in time and money.

Second: Our recent purchase by Sun means that our certification data will soon be rolled into Sun's certification database. Please help me out by having your data up to date.

So how do you update your address? You can update your data at Pearson VUE's website or send an email to Certification@MySQL.com

Please take two minutes today to save hours of very hard work in the future!

Note to those of you that have written me with words of appreciation and encouragement as well as suggestions for new pop quizzes: First: Thanks for the kind words! Second: If you’re awaiting an answer, please rest assured that I do read your mail! I get mails relating to the pop quizzes daily, so I’m having to work on this in batch mode. You will get an answer from me in a few days.

Today’s question comes from Bertrand Gorge, who tells me he uses this as a test question during interviews. So if you’re looking to work for him, make sure you’ve understood this!

The following two queries do not return the same result. Why ?

SELECT table1.*
FROM table1 LEFT JOIN table2
ON table2.table1_id = table1.id AND table2.val < 5

SELECT table1.*
FROM table1 LEFT JOIN table2
ON table2.table1_id = table1.id WHERE table2.val …

JavaScript? Check. Ajax? Check. “Beta” tag? Check. Bright colors? Check. Big fonts? Check. Rounded corners? Check*.

In a fit of “someone really ought to have made such a tool already” and wanting to play a bit with Javascript and DOM, I humbly present my Web 2.0 - compliant MySQL DATE_FORMAT() and PHP DATE() tool.

Not very fancy or anything, but it should go some way toward saving you the effort of looking up formatting codes and running your scripts for the nth time to check whether things work or not.

Any and all suggestions for improvements are appreciated!

Virtual Hosting Howto With Virtualmin On CentOS 5.1

This tutorial shows how to set up a CentOS 5.x server to offer all services needed by virtual web hosters. These include web hosting, smtp server with (SMTP-AUTH and TLS, SPF, DKIM, Domainkeys), DNS, FTP, MySQL, POP3/IMAP, Firewall, Webalizer for stats.

This poll did not get a lot of voters but I thought I would post the results to show you the priority of the individuals that did vote. Poll: What is your highest priority with MySQL?Performance Tuning  20% Backup and Recovery 20% Monitoring and Management 16 % High Availability 16% Scalability 12% Storage 10% BI and Reporting 3% Business Strategy 3%

Virtual Hosting Howto With Virtualmin On CentOS 5.1

This tutorial shows how to set up a CentOS 5.x server to offer all services needed by virtual web hosters. These include web hosting, smtp server with (SMTP-AUTH and TLS, SPF, DKIM, Domainkeys), DNS, FTP, MySQL, POP3/IMAP, Firewall, Webalizer for stats.

MySQL configurations cover the range from developers installing a simple MySQL database for a LAMP application to the largest Internet companies using MySQL to deliver web content.There are two different profiles that cover this range for installing,  configuring and managing MySQL database servers:Profile 1: Individuals or small organizations that wants to use MySQL to create a simple database