In the blog about designing binary relationships, I briefly described crow’s foot notation. Crow’s foot notation is a design technique that visually explains our relationship between tables.
In order to understand crow’s foot notation, we must first understand the basics of database design. I recommend you read the previous blogs listed to familiarize yourself with all of the database relationship concepts:
Relationships
Parent-Child Tables
Designing Binary Relationships
Cardinality
Cardinality refers to the relationship between a row of one table and a row of another table. The only two options for cardinality are one or many.
Example: Think of a credit card company that has two tables: a table for the person who gets the card and a table for the card itself. A row from the card_holder table would have a relationship with a row in the card table because the card_holder holds the card.