Internal Server Error 500 in Magento

Many of us who started experimenting with this interface and tried to place various values for Base URL, came to a dead end where Magento breaks.  Usually, we get Internal Server Error 500 with each page load. The problem lies in the fact that we can no longer open the Magento administration to correct the error. What needs to be done in such a scenario?

One of our clients wrote me a message today:
I have put www.mydomain.com in a bad spot. I changed the base URL to {{base_URL}} and now im getting a 500 server error on both the front end and the admin panel. I have looked through the database and cannot find the right field to change this value back. Can you point me in the right direction?

The client went to System> Configuration> Web> Unsecure and placed an invalid value for Base URL field. Beware of this field. Unfortunately, Magento just updates it without any pre-warnings, but change of this specific value can cause Magento to crash.

Usually, we get an error that looks like this:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@mysite.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

The client was on right path to find a solution. We need to open MySQL (usually via php MyAdmin) and find core_config_data table. Once there, manually update 2 rows:

   1. config_id:3 web/unsecure/base_url => http://www.mydomain.com/
   2. config_id:4 web/secure/base_url => https://www.mydomain.com/

Everything should work now. Hope this will help someone.

Source : http://asia-connect.com.vn/