IDEF1X Notation
Go Up to Setting the Relationship Notation
Identifying versus Non-Identify means that the parent entity identifies the child e.g. City contains (identifying) State allows us to have two Cities of the same name that can be made unique by the State within they exist. e.g. Dover in Delaware, Dover in Minnesota.
Non Specific Relationships, also referred to as a "many to many relationship", is an association between two entities in which each instance of the first entity is associated with zero, one, or many instances of the second entity and each instance of the second entity is associated with zero, one, or many instances of the first entity. These cannot be created in most databases so a special relationship exists to model it until it can be resolved with an associative entity.
Multiplicity is shown with adornments on each end of the line and shows the number of each Parent to each Child entity as a range with lower and upper values.You read the line from each direction. e.g. State must have one to many Cities. City must have one and only one State.
The following illustrates how relationships are presented in ER/Studio Data Architect using the IDEF1X notation:
IE is considered to be semantically stronger than IDEF1X, supporting more abstract approaches to data modeling. IE is more flexible in supporting subtypes, permitting roll up (generalization) and roll down (specialization) transformations. In addition, primary keys are less prominent in the IE notation; therefore, its practitioners are less likely to think about logical key choice prematurely.