Multiple WordPress Installation into a single database is possible and it’s not so difficult. If your hosting package only allows you one MySQL database, then this video is for you.
WordPress assigns the table prefix wp_ to its MySQL database tables, but this prefix can be anything you choose. This allows you to create unique identifiers for each blog in your database. For example, let’s say you have three blogs to set up, with the names Athos, Porthos, and Aramis. You should substitute the prefix wp_ in each blog’s
wp-config.php:
Main blog:
$table_prefix = 'athos_';
Projects blog:
$table_prefix = 'porthos_';
Test blog:
$table_prefix = 'aramis_';
As noted, you may use a prefix of your own making. Those provided here are for example only.
Video Credit: wordpress.tv
