Diagramming Conventions and Symbols - Database Design and Development: An Essential Guide for IT Professionals - page 683

Entity Type: Strong

Entity Name

OR

Entity Name

OR

Entity Name

Entity Type: Weak

Entity Name

OR

Entity Name

OR

Entity Name

Relationship: Strong

Relationship
Name

Relationship
Name

OR

OR Relationship

Name

Relationship: Weak

Relationship
Name

Relationship
Name

Relationship
Name

OR OR

Attribute

Attribute
Name

OR

Attribute
Name