Relations and nested writing
How objects are connected to each other, and how you create, link, change or remove connected objects in the same request.
Topics in this subject area
- 1.Relation types and recursive flags
The four relation types and the permissions CREATE, UPDATE and DELETE, which define what CDMS may do across a relation.
- 2.The four cases in nested writing
Two questions decide whether a child object is created, changed, only linked or rejected: Does it have an
id? Is the matching flag set? - 3.Lists as target state
A list in the payload describes what the list should look like afterwards. This page explains what happens to members that no longer appear.
- 4.Both sides of a relation
CDMS maintains the other side of a relation automatically. Why the client should not send the back reference.
- 5.Many-to-many through a join table
How n:m relations are mapped through a separate join model, and what this means when writing.
- 6.Cycle protection
How CDMS prevents nested reading or writing from going around in circles.