sys-key-constraints-transact-sql.md

title	sys.key_constraints (Transact-SQL)
description	sys.key_constraints (Transact-SQL)
author	rwestMSFT
ms.author	randolphwest
ms.date	03/15/2017
ms.service	sql
ms.subservice	system-objects
ms.topic	reference
ms.custom	ignite-2025
f1_keywords	sys.key_constraints key_constraints sys.key_constraints_TSQL key_constraints_TSQL
helpviewer_keywords	sys.key_constraints catalog view
dev_langs	TSQL
monikerRange	>=aps-pdw-2016 || =azuresqldb-current || =azure-sqldw-latest || >=sql-server-2016 || >=sql-server-linux-2017 || =azuresqldb-mi-current || =fabric || =fabric-sqldb

sys.key_constraints (Transact-SQL)

[!INCLUDE sql-asdb-asdbmi-asa-pdw-fabricdw-fabric]

Contains a row for each object that is a primary key or unique constraint. Includes sys.objects.type PK and UQ.

Column name	Data type	Description
<Columns inherited from sys.objects>		For a list of columns that this view inherits, see sys.objects (Transact-SQL).
unique_index_id	int	ID of the corresponding unique index in the parent object that was created to enforce this constraint.
is_system_named	bit	1 = Name was generated by system. 0 = Name was supplied by the user.

Permissions

[!INCLUDEssCatViewPerm] For more information, see Metadata Visibility Configuration.

See Also

Object Catalog Views (Transact-SQL)
Catalog Views (Transact-SQL)
Querying the SQL Server System Catalog FAQ