As such, the foreign key columns of the child table often refer to the primary key columns of the parent table. The film table is called the parent table or referenced table, and the inventory table is known as the child table or referencing table.

The model that we saw in the intro depicts a one-to-many relationship between the film and inventory tables whereby a film entity (1 row) may link to zero or more entities (rows) in the inventory table.

This blog will cover how foreign keys work as well as how to create a foreign key constraint in MySQL using Navicat 16 for MySQL. In relational database, referential integrity between tables is enforced using foreign key constraints. Common fields (usually IDs) are then employed to maintain their relationship. A Guide to MySQL Foreign Key Constraints by Robert Gravelleĭuring the process of normalization, groups of fields that represent a distinct entity are removed from a larger and/or more central table to a separate one.