# A company identifies customers by email, but emails change

Canonical URL: <https://datadriven.io/problems/a-company-identifies-customers-by-email-but-emails-change-f3eda858>

Domain: Data Modeling · Difficulty: medium

## Problem

A company identifies customers by email, but emails change. Design a customers table with a stable surrogate primary key instead of using a business attribute as the identifier.

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