One-to-One Relationship

A relationship where each row can relate to at most one row on the other side.

What is One-to-One Relationship in a relational database?

One-to-One Relationship — A relationship where each row can relate to at most one row on the other side.

CREATE TABLE customer_profile (
    customer_id INTEGER PRIMARY KEY
        REFERENCES customer (customer_id)
);

Level: Novice · More Database terms at this level

Updated September 27, 2026