Can a Single Column Serve as Multiple Foreign Keys in a Database?

Can You Reference One Column as Multiple Foreign Keys?

In the realm of database management, you may encounter situations where you want to connect data from different tables using foreign keys. However, what happens when you need to reference a single column in one table as a foreign key to multiple other tables?

The Challenge

Consider the following scenario: you have a table called pdf_created that contains data from a parsed PDF document, including item_types and corresponding item_ids. You want to reference this item_id column as a foreign key in several other tables, such as product, service, and header.

The Solution

It's important to note that it's not possible to create a foreign key constraint that references a column in multiple tables. However, you can still create a foreign key relationship by using the item_id column as a foreign key without the constraint.

A foreign key, essentially, is a value that matches another table's primary key, enabling joins between records. Even without a foreign key constraint, you can use the item_id field to connect records in pdf_created to corresponding records in product, service, and header tables.

So, while it's not possible to create multiple foreign key constraints to the same column, you can still utilize this technique to reference other records in your database.

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