How you tried in your xml file add something like
<install>
<sql>
<file charset="utf8" driver="mysql">install.sql</file>
</sql>
</install>
<uninstall>
<sql>
<file charset="utf8" driver="mysql">uninstall.sql</file>
</sql>
</uninstall>
And the install.sql file should have the query. Also make sure the DB user have permission to add new tables.
Its Done!