16.10 - Keys - Teradata Database

Teradata Database SQL Fundamentals

Product
Teradata Database
Release Number
16.10
Release Date
June 2017
Content Type
Programming Reference
Publication ID
B035-1141-161K
Language
English (United States)

A primary key is a column, or combination of columns, in a table that uniquely identifies each row in the table. The values defining a primary key for a table:

  • Must be unique
  • Cannot change
  • Cannot be null

A foreign key is a column, or combination of columns, in a table that is also the primary key in one or more additional tables in the same database. Foreign keys provide a mechanism to link related tables based on key values.