How to Add Foreign Key in MS Access

Quick summary

Adding a foreign key in Microsoft Access links two tables through the Relationships tool, enforcing referential integrity so child records always match a valid parent entry. This step-by-step process uses the Database Tools ribbon to define and save table relationships without writing any SQL.

Steps

1. Launch Microsoft Access and open the database where you want to add the foreign key, ensuring you have two tables ready.
2. Go to the Database Tools tab in the ribbon.
3. Click on Relationships to open the Relationships window.
4. In the Relationships window, add both the parent and child tables by clicking Add Selected Tables.
5. Drag the primary key field from the parent table and drop it onto the corresponding field in the child table.
6. When the Edit Relationships dialog box appears, verify that the fields match correctly.
7. Select Enforce Referential Integrity to prevent invalid entries in the child table that don't exist in the parent table.
8. Click Create to establish the relationship.
9. Click Save to save the relationships and finalize the foreign key configuration.