Use the TADPhysMySQLDriverLink component to link the MySQL Server driver to an application. In general it is enough to only include uADPhysMySQL unit into your application uses clause. 

The TADPhysMySQLDriverLink component may be used to specify:

• VendorHome - the MySQL installation root folder;
• VendorLib - the name and optional path to the MySQL client library.

All properties have default values appropriate for most case. To have an effect all property changes must be performed before first connection through this driver or use the Release method.

TADPhysMySQLDriverLink = class(TADPhysDriverLink);

Configuring Drivers, Connect to MySQL Server