Primary Key

Definitions

1. A column or combination of columns in a database table that uniquely identifies each row, enforcing both a uniqueness constraint and a NOT NULL constraint. The primary key also typically serves as the table's clustered index, determining the physical storage order of rows.

   In plain English: The unique identifier for each row in a database table — like a social security number for a record — ensuring no two rows are the same.

   Example: "We use a UUID as the primary key instead of an auto-incrementing integer so IDs aren't guessable."

Related Terms

• Query
• Left Join
• MySQL
• PostgreSQL
• Query Builder
• Raw SQL
• RDBMS
• SQLite
• Complex Type