Returns one row for each column that is constrained as a key in the current database. This information schema view returns information about the objects to which the current user has permissions.
To retrieve information from these views, specify the fully qualified name of INFORMATION_SCHEMA.view_name.
|
Column name
|
Data type
|
Description
|
|---|
|
CONSTRAINT_CATALOG
|
nvarchar(128)
|
Constraint qualifier.
|
|
CONSTRAINT_SCHEMA
|
nvarchar(128)
|
Name of schema that contains the constraint.
.gif) Important:
Do not use INFORMATION_SCHEMA views to determine the schema of an object. The only reliable way to find the schema of an object is to query the sys.objects catalog view or the OBJECT_SCHEMA_NAME function.
|
|
CONSTRAINT_NAME
|
nvarchar(128)
|
Constraint name.
|
|
TABLE_CATALOG
|
nvarchar(128)
|
Table qualifier.
|
|
TABLE_SCHEMA
|
nvarchar(128)
|
Name of schema that contains the table.
Important:
Do not use INFORMATION_SCHEMA views to determine the schema of an object. The only reliable way to find the schema of an object is to query the sys.objects catalog view or the OBJECT_SCHEMA_NAME function.
|
|
TABLE_NAME
|
nvarchar(128)
|
Table name.
|
|
COLUMN_NAME
|
nvarchar(128)
|
Column name.
|
|
ORDINAL_POSITION
|
int
|
Column ordinal position.
|
The following example returns information about each column that is defined as a key column in a constraint.
USE AdventureWorks;
GO
SELECT CONSTRAINT_SCHEMA, CONSTRAINT_NAME, TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
ORDER BY TABLE_SCHEMA, TABLE_NAME;
Reference
System Views (Transact-SQL)
Information Schema Views (Transact-SQL)
sys.columns (Transact-SQL)
sys.indexes (Transact-SQL)
sys.objects (Transact-SQL)
sys.foreign_keys (Transact-SQL)
sys.key_constraints (Transact-SQL)
OBJECT_SCHEMA_NAME (Transact-SQL)
Other Resources
Querying the SQL Server System Catalog
Help and Information
Getting SQL Server 2008 Assistance