Originally Posted by Rhyan

Are the 3 websites hosted on the same server?

If the 3 websites are not stored on the same server, then the server where the mysql database is should allow connections from the internet, not only localhost requests.

If the sites are hosted on a public webserver, I doubt that the server would allow access from the internet, as it is potentially unsafe.

Still, if you can perform grants, you can configure a read-only access to the database for a user, explicitly allowing access from the IP of the website that needs to acces the database. It seems confusing, so I will explain like this:

1. website 1 holds the database.
2. website 2 needs access to the database of website 1 from ip 1.2.3.4 .

Create a user named e.g. web2 with pass web2 in the database server.
Grant to user web2 SELECT on DATABASE.* from host with ip 1.2.3.4.

open port in firewall at website1 server for access to the database server normally on port 3306 for mysql.

it should work this way.

If you need any info check resources available on mysql.com or check the hosting server help and faq manuals and sections on how to allow access, grant permissions, etc.