Below are several examples of Conceptual Data Model relationships and their meaning, click the links to expand the examples.
Onetomany relationships

Each division can have zero or more employees.
Each employee belongs to zero or 1 division.
This is a nonidentifying relationship.


Each division must have 1 or more employees.
Each employee belongs to zero or 1 division.
This is a nonidentifying relationship.


Each division can have zero or more employees.
Each employee belongs to 1 division.
This is a nonidentifying relationship.


Each division must have 1 or more employees.
Each employee belongs to 1 division.
This is a nonidentifying relationship.

Onetoone relationships

Each team works on zero or one project.
Each project is being worked on by no team or just one teams.
This is a nonidentifying relationship.


Each team works on one project.
Each project is being worked on by no team or just one team.
This is a nonidentifying relationship.


Each team works on zero or one project.
Each project is being worked on by one team.
This is a nonidentifying relationship.


Each team works on one project.
Each project is being worked on by one team.
This is a nonidentifying relationship.

Manytomany relationships

Each employee belongs to zero or more divisions.
Each division has zero or more employees.
This is a nonidentifying relationship.


Each employee must belong to 1 or more divisions.
Each division has zero or more employees.
This is a nonidentifying relationship.


Each employee belongs to zero or more divisions.
Each division has 1 or more employees.
This is a nonidentifying relationship.


Each employee must belong to 1 or more divisions.
Each division has 1 or more employees.
This is a nonidentifying relationship.

