Physical Foreign Key

A PhysicalForeignKey represents a foreign key constraint between two tables in a relational database. The foreign key constraint enforces referential integrity by ensuring that the values in the foreign key column(s) of one table (the referencing table) correspond to the values in the primary key or unique column(s) of another table (the referenced table).

In a Relational Diagram, the PhysicalForeignKey template is used to model relationships between tables that are based on foreign key constraints. This helps to maintain data consistency and integrity across related tables in the database schema.

Example: In a Relational Diagram for a system that manages an online store, you might have two tables: “Orders” and “Customers”. The “Orders” table has a column called “customer_id” that represents the customer who placed the order, and the “Customers” table has a column called “id” that serves as the primary key for each customer record. To model the relationship between these tables and enforce referential integrity, you can create a PhysicalForeignKey constraint from the “customer_id” column in the “Orders” table to the “id” column in the “Customers” table. This constraint ensures that every order in the “Orders” table must have a valid “customer_id” that corresponds to an existing record in the “Customers” table.

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