Use primary keys to identify records

- [Narrator] Relational databases only work … if the system can uniquely identify each record in a table. … They do this using a column that's been designated … as the table's primary key. … Primary keys are used everywhere in our daily lives. … Your library card number or bank account number … are the primary keys to your accounts. … Your email address is often used by websites … to uniquely identify you from every other user, … and it acts as the primary key for retrieving … your shopping history or your social media posts. … The government uses your social security number … and driver's license numbers to make sure … that you've paid your taxes, … and verify eligibility for benefit programs. … These unique identifiers are all critically important … to the functionality of the systems that you participate in. … Beyond the databases that identify you as a unique person, … businesses need to have unique product numbers … so that they ship the correct items to customers. … Books have ISBN numbers and computers have serial numbers. …