We're trying to understand how we can update a Data Extension from an event. I note that the contactEvents REST method lets you do this but requires a
I note the Data Designer glossary explains:
A root relationship represents a one-to-one relationship between a contact record and a data extension that acts as a source for contact information. A root relationship can only take place between the contact record and a single data extension. That contact record relates via the contact key or contact ID to the data extension.
This implies that a relationship needs to exist between a 'Contact Record' and Data Extension. That's fine, but how do you create this relationship and how can we get the
contactID values using the API so we can use this in events?