Database Schema – Primary and Foreign Keys

Concept

• A schema is the blueprint that defines the structure of a database (tables, columns, data types).
• A primary key uniquely identifies each record in a table.
• A foreign key links records between different tables.

Example

• Workout Table: Has a primary key workoutID.
• Exercise Table: Has a primary key exerciseID.
• WorkoutExercise Join Table: Contains both workoutID (foreign key to Workouts) and exerciseID (foreign key to Exercises).

Source

• Wikipedia - Database Schema