db.xml

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.concrete5.org/doctrine-xml/0.5"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.concrete5.org/doctrine-xml/0.5 http://concrete5.github.io/doctrine-xml/doctrine-xml-0.5.xsd">

    <table name="btJoin">
        <field name="bID" type="integer">
            <unsigned/>
            <key/>
        </field>
    </table>

    <table name="btJoinUser">
        <field name="bID" type="integer">
            <unsigned/>
            <key/>
        </field>
        <field name="uID" type="integer">
            <unsigned/>
            <key/>
        </field>
        <field name="dateTime" type="timestamp">
            <deftimestamp/>
        </field>
        <field name="comment" type="text">
            <default value=""/>
        </field>
        <references table="btJoin" onupdate="cascade" ondelete="cascade">
            <column local="bID" foreign="bID" />
        </references>
    </table>

</schema>