PRIMARY KEY Constraints Versus UNIQUE Constraints - Advanced SQL Engine - Teradata Database

SQL Data Definition Language Detailed Topics

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
17.00
Published
June 2020
Language
English (United States)
Last Update
2021-01-24
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B035-1184
lifecycle
previous
Product Category
Teradata Vantage™

UNIQUE and PRIMARY KEY constraints can only be defined on a column set that is also constrained to be NOT NULL.

To create a composite, or multicolumn, primary key for a table, you must specify the PRIMARY KEY constraint at the table level, not the column level.

Both UNIQUE and PRIMARY KEY constraints can be defined on a UDT column.

Teradata Database also supports the related constraints UNIQUE INDEX and UNIQUE PRIMARY INDEX.