I use a plugin called Robots Meta. This plugin makes it really easy to control the way robots / spiders crawl and index your blog. You can for instance prevent indexing of your login, register and admin pages by adding noindex robots meta tags or disable your author and date-based archives if you don’t use them. These are just two of many other features. When setup correctly it will optimize your blog for better search engine indexing.

I have noticed a bug with the plugin however. One of the functionalities of this plugin is that you can add index and follow rules per post or page. But after installation editing these options on posts or pages didn’t seem to be saved always reverting back to the original option. Looking in my error logs I noticed a lot of database errors as shown below:

WordPress database error Unknown column 'robotsmeta' in 'field list' for query UPDATE wp_posts SET robotsmeta = '' WHERE ID = 284 made by ...
WordPress database error Unknown column 'robotsmeta' in 'field list' for query UPDATE wp_posts SET robotsmeta = '' WHERE ID = 284 made by ...
WordPress database error Unknown column 'robotsmeta' in 'field list' for query UPDATE wp_posts SET robotsmeta = '' WHERE ID = 284 made by ...

Looking into it further I came to the conclusion that the plugin on activation should have created a new column to the post and pages database table (wp_posts) but failed to do so. Below are two ways to get this working and get rid of those nasty database errors.

Solution 1: edit the source files of the plugin

You can force the plugin to create the needed column by editing the plugin source file. Open the file called robots-meta.php which is located under /wp-content/plugins/robots-meta/. Add the following code right before ?> at the end of the file.

robotsmeta_update();

Solution 2: adding the column manually

I however didnt want to mess with the source code of the plugin. Although the fix above seem to work fine I can’t tell for sure if it also has any side effects. Instead I added the column to the database by manually using phpMyAdmin. Follow these steps to add the column by hand.

1. Open your database in phpMyAdmin and click on the database table called wp_posts from the left pane.
2. Click on the tab called structure
3. Scroll towards the end of the table where you see an option called Add [1] fields. Add 1 new field to the end of the table. These are default options so all you have to do is press Start.
4. Enter the settings as shown below.
   
   I copied these settings from the source code of the plugin so they will work for sure. Then hit the start button to add the column
5. With the column now in place you can start to update your posts and pages and edit the index and follow settings for each post or page.