Table Links
A description of Table relationship types which are also defined as Associations
A description of Table relationship types which are also defined as Associations
Entity-relationship (ER) models are based on real-world entities and their relationships. Developers understand these systems just by looking at the ER diagram. ER models are normally represented by ER diagrams.
An ER diagram basically has three components:
Entities − It is a real-world thing that can be a person, place, or even a concept. For example, Department, Admin, Courses, Teachers, Students, Building, etc are some of the entities of a School Management System.
Attributes − An entity that contains a real-world property called an attribute. For example, the entity employee has properties like employee id, salary, age, etc.
Relationship − Relationship tells how two attributes are related. For example, an employee works for a department.
A One-to-Many relationship in a DBMS is a relationship between instances of an entity with more than one instance of another entity.
A Many-to-One relationship in a DBMS is a relationship between more than one instance of an entity with one instance of another entity.
A Many-to-Many relationship in a DBMS is a relationship between more than one instance of an entity with more than one instance of another entity i.e. both the entities can have many relationships between each other.
A One-to-One Relationship is an association with the same entity between the same instances represented by the same role group.
For more information, go to https://docs.microsoft.com/en-us/ef/ef6/fundamentals/relationship
