Over the past 10 years, the MySQL database has become incredibly popular on the Web. Every WordPress blog is driven by a MySQL database, which contains the blog’s posts, settings, comments and much more.

While plug-ins and even coding hacks can solve some problems and achieve some tasks, sometimes you don’t have any other choice than to execute SQL commands in phpMyAdmin or directly to the database via SSH. Let’s take a look at 8 useful SQL hacks for WordPress. Each section of this post presents a problem, suggests a solution and provides an explanation to help you understand the solution.

1. Creating a Backup of Your Database

The problem. While the tips in the rest of this post have been tested, you should definitely not try any of them without first having a proper backup of your MySQL database.

The solution. To create a manual backup of your WordPress database, follow these simple steps:

1. Log in to phpMyAdmin and select your WordPress database.
2. Once done, click the “Export” button located in the horizontal menu.
3. Choose a compression method (personally, I use gzip), and click the “Execute” button.
4. Your browser will ask you if you want to download the backup. Of course, select “Yes,” and then store it on your hard drive.

Explanation. Note that creating a backup of your WordPress database can be more easily executed with the WP-DB-Backup plug-in. WordPress users should install this plug-in if they have not yet done so and create regular backups of their data.

2. Batch Delete Post Revisions

The problem. Post revisions, a new WordPress 2.6 feature, can be very useful, but they also increase the size of your MySQL database. Sure, you can manually delete posts revisions, but that’s very long and boring work.

The solution. The solution to this problem is simple: we batch delete post revisions by using a simple SQL query. The result can be almost unbelievable if you have a lot of posts: Your database size will be reduced by half!

1. Log in to phpMyAdmin and select your WordPress database.
2. Click the “SQL” button. Paste the following code in the SQL command window:
   
   

   • DELETE FROM wp_posts WHERE post_type = “revision”;
     

   DELETE FROM wp_posts WHERE post_type = "revision";

3. You’re done. Depending on how many posts you had in your WordPress database, you may have saved lots of precious space!

Code explanation. The wp_posts table has a field named post_type. This field can have one of many values, such as “post,” “page” or “revision.” When we want to get rid of post revisions, we simply run a command to delete any entry in the wp_posts table in which the post_type field is equal to “revision.”

Source:

• How to: Batch delete post revisions

Read the rest of this entry »

DD_belatedPNG is a fresh IE6 PNG fix script with features where other solutions are missing.

It doesn’t use MSIE AlphaImageLoader filter so, it succesfully renders background-repeat and background-position.

The script also fixes the IE6 grey background problem.

How to use it?

Very simple.

Read the rest of this entry »