Entity Relationship Diagram – Crow's Foot notation


Introduction

Entity Relationship Diagram (ERD) is one of the most common modeling techniques. Crow’s foot notation is one of the several ERD notations are available. It was invented by Gordon Everest. Originally, it was known as “inverted arrow” but now as “fork”. For cardinality, a fork or crow’s foot naturally indicates “many”, by its many toes.

Crow’s Foot notation is used in Information Engineering and Barker’s Notation. Crow’s Foot diagrams symbolize entities as boxes, and relationships as lines between the boxes. Different shapes at the ends of these lines represent the cardinality of the relationship.

ER Diagram

Components used in the creation of an ERD

Components used in the creation of an ER Digram

Cardinality and modality are indicated at both ends of the relationship line. Once this has been done, the relationships are read as being 1 to 1 (1:1), 1 to many (1:M), or many to many (M:M).

Cardinality

How to use DIO to create ER Diagram in Crow’s Foot notation

Download Dia Diagram Editor

1. DIO-Crows Foot Notation

2. DIO-Crows Foot Notation

3. DIO-Crows Foot Notation

4. DIO-Crows Foot Notation

5. DIO-Crows Foot Notation

6. DIO-Crows Foot Notation

One to one

 8. One to One - DIO-Crows Foot Notation

One to Many

 9. One to Many - DIO-Crows Foot Notation

Many to Many

 10. Many to Many - DIO-Crows Foot Notation

One to Many

11. One to Many - DIO-Crows Foot Notation

12. DIO-Crows Foot Notation

 

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