Opened 10 years ago
Closed 10 years ago
#10 closed defect (fixed)
Entity Relationship Diagram and Relational model
| Reported-by: | 139037 | Owned by: | somebody |
|---|---|---|---|
| Priority: | major | Milestone: | |
| Component: | component1 | Version: | |
| Keywords: | Cc: |
Description
Entity Relationship Diagram
The basic constructs of the ER model are entities, relationships, and attributes. Entities are concepts, real or abstract, about which information is collected. As entities in the ER diagram which is below are: Appointment, Patient, lab, examination.
Relational model
The transformation of E-R diagram into relational model is an important step, because this model defines the tables that should be implemented in Access. This transformation is also very important because there can be seen in details which attributes are used as primary keys and which are foreign keys, this scheme also provides a better distinction between identifiers and descriptors which were mentioned above.
The organization of data into relational tables is also known as the logical view of the database. That is the form in which a relational database presents data to the user and the programmer.
