What is the Relational modeller?
The Relational modeller allows a user to create parent/child relationships between object classes.
It not only provides a visual display of these relationships, but is also the mechanism by which child object classes are made available to the parent object class.
This means that when a relationship has been configured and saved in the relational modeller, child object classes can be added to the create/edit view of the parent object class.
It also means that the parent record will have access to the data held in related child records, and that this data can be merged into documents and send message actors.
The screenshot below shows a relational modeller with two separate relationships.
Relationship 1: left-hand side
The first relationship, on the left-hand side, consists of three object classes, each at a different level:
- Employee Management (HR) is at the top - we call this the root parent.
- Employee Management (HR) has one direct child - Employees. The ratio of parent record to each child record is 1:1. Note that object class Employees is not only a child. It is a parent to object class Employment Contracts.
- Employment Contracts is a direct child of Employees. The ratio of Employee to Employee Contracts is one to many, shown as 1:N. During the life-cycle of any employee, it is likely that they will have more than one contract as the company expands or their job role changes, etc.
Relationship 2: right-hand side
The second relationship, on the right, has a root parent object class called Mortgage Application.
It has four direct child object classes, each with a 1:1 ratio with the parent. This means that a Mortgage Application record can have no more than one Applicant 1 record, one Applicant 2 record, one Property, and one Lender.
Find out more about creating your relational model.
Useful info
For any user creating or editing the relational model:
- There is one relational modeller per instance of Catalyst.
- The maximum number of root parent object classes is five.
- An object class can only appear once in the relational model. It will be greyed out on the Object class sidebar once dropped onto the canvas.
- The maximum number of child object classes another object class can have is five.
- The maximum number of parent/child levels for any relationship is five. This limit is from the root parent (or top object class) down to the deepest descendent.
- A record in a parent object class can be created without any child objects, or it may contain some, eg in the above example, a Mortgage Application may be created with an Applicant 1 record and a Property. It may be edited later to include a Lender. It does not have to ever include an Applicant 2.