If you want to work directly with the MySql provider you could add
<%@ Import Namespace="MySql.Data.MySqlClient" %>
or you could add this:
<%@ Import Namespace="mojoPortal.Data" %>
which should allow you to use our MySqlHelper class which has methods such as ExecuteReader, ExecuteNonoQuery, ExecuteScalar
You can study mojoportal source code in the data layer for MySql to find good examples.
We also have a SavedQuery class that lets you save and retrieve query statements and our DatabaseHelper which helps execute them, useful for quick and dirty features but not how I would typically develop anything complex. There is an article here http://www.mojoportal.com/populating-a-chart-with-data-from-a-saved-query.aspx and also an article here about our built in query tool http://www.mojoportal.com/using-the-sql-query-tool.aspx
Hope it helps,