Architecting and designing > Data modeling > Components of an entity relation diagram > Creating project models and associated diagrams > ER or IDEF1X model diagrams
  
ER or IDEF1X model diagrams
An Entity Relation or IDEF1X Model diagram is a pictorial representation of the entire system under design. It includes all entities, attributes, access paths, and relationships that have been defined as belonging to the project model.
The Model diagram is automatically updated each time the diagram is opened or the user invokes the Refresh command from the Dictionary menu.
Note A Project Model contains zero or one Model diagram and zero, and one or many Subject Area diagrams.
Assume that other users are working on Subject Area diagrams in this project model. When the Model is refreshed:
All entities on subject area diagrams in this project model are added to the Model diagram.
All relationships on subject area diagrams in this project model are added to the Model diagram.
All entities and relations that have been removed from the project model since the last refresh are deleted from the diagram.
See also Subject area diagrams.
See also
Creating project models and associated diagrams