Parameterization of the box:

1. Graph type selector Chord
2. SQL statement to execute, in this case:

<select>
    <columns>
        genre.name <alias name='x_name'/>,
        employee.firstname || ' ' || employee.lastname <alias name='y_name'/>,
        SUM(invoice.total) <alias name='value'/>
    </columns>    
    <from table='track'>
        <join table='genre'>
            <on>track.genreid = genre.genreid</on>
        </join>
        <join table='invoiceline'>
            <on>track.trackid = invoiceline.trackid</on>
            <join table='invoice'>
                <on>invoiceline.invoiceid = invoice.invoiceid</on>
                <join table='customer'>
                    <on>invoice.customerid = customer.customerid</on>
                    <join table='employee'>
                        <on>employee.employeeid = customer.supportrepid</on>
                    </join>
                </join>
            </join>
        </join>
    </from>
    <group>1,2</group>
</select>

* We search for each employee the invoice that he has produced for each genre of music

INPUTS:

• x_name: Elements of the X axis (Source)
• y_name: Y axis elements (Target)
• value: Relationship between these two elements.

Each entry contains the information corresponding to the relationship between two unique elements of the graph.

In this type of graph the user can interact to show only the relationships that belong to one of the nodes.

• (1) Show relations of a single node: When placing the mouse on one of the nodes, only the relationships where this node takes part will be marked, either as a receiver or as an emitter.