How to change Joomla root URL

If install Joomla on a remote hosting that can install multiple website, you should put all joomla files into a sub-folder, and install joomla database into a seperate database or a new database. and then maybe you have a seperate domain name for your new joomla website. You can setup all steps that just follow  regular steps that multiple websites installed into the same space and add a new domain name to point to your new sub-folder, normally, you should think your new website prepare to work; just one step left: change the root URL of your new website.

Now maybe you just prepare to do like what you did before - access into the database and try to find some field indicate the root URL, but, when you scan all and brower all database, you find you can not find a field store the value of root URL ! strange! where it is ? Joomla doesn't use database to store its system root URL ?

Yes! Joomla really doesn't use database store the root URL, it uses config file: in the root of your joomla website, you can find a file named "configuration.php", open it and you will find the root URL - "$mosConfig_live_site", change its value to your final root URL.

Done!