To someone who hasn’t dealt with this problem before, this issue probably seems pretty intimidating (at least I think it did to me when I first got it). However, this is most likely a simple fix.

Arriving at the Problem

First, let’s talk about how I came about this problem today so you can avoid it in the future.

To speed things up, I like to keep a copy of the most recent version of WordPress on my computer with a few modifications. One thing I modify is the wp-config.php file; here are some of the changes:

/** MY CHANGES **/

// creates fewer database queries, thus improving performance
define('WP_HOME', 'http://URL.com');
define('WP_SITEURL', 'http://URL.com');

This will screw things up if I don’t replace 'http://URL.com' with the correct URL. More specifically, I get the “clear your old database tables first” message from WordPress. This is what happened today when I transferred a theme from my server to a client’s.

The Solution

<!-- EDIT -->
Quickest and easiest way in the comments. I haven’t tested it yet, but I know and trust the source.

1. Log in to phpMyAdmin (or other database management tool).

   You should be able to find phpMyAdmin in the control panel of your hosting account.

   With lunarpages, you need to click on MySQL Databases and scroll to the very bottom and click the phpMyAdmin link.

   With AT&T, you get to the control panel by adding /ControlPanel/ to the end of your URL.

   1. Once you log in, click on databases in the left column.
   2. If you haven’t already enabled MySQL, click MySQL under databases,
   3. create a password,
   4. and click the enable button on the right.
   5. Right beneath MySQL, click phpMyAdmin
   6. and enable it by clicking the button on the right.
   7. Then click the link that reads “Administer MySQL with phpMyAdmin.” Log in and you’ll be in phpMyAdmin.

   
   
   

   I haven’t had to do this with any other hosts so if you need help, contact your host, leave a comment, or send me an email and I’ll do my best to help you figure it out.

2. After logging in, you should be on a page that has a sidebar on the left with a list of all your databases. Click on the name of the database from which you need to clear tables.



<!-- I’m pretty sure this next step is irreversible, so make sure you’re on the right database -->

3. Now you just need to select all the tables that begin with the “wp_” prefix and choose “Drop” from the drop-down menu.
4. Make sure your wp-config.php file has all the correct information in it, and go to http://example.com/wp-admin/install.php/.

You should be good to go now. If you’re still having trouble, leave a comment and I’ll see what I can do. Also, if you have anything to add, feel free to do so in the comments.