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KEY_COLUMN_USAGE (Transact-SQL)

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.

Important noteImportant
Do not use INFORMATION_SCHEMA views to determine the schema of an object. The only reliable way to find the schema of a object is to query the sys.objects catalog view.

CONSTRAINT_NAME

nvarchar(128)

Constraint name.

TABLE_CATALOG

nvarchar(128)

Table qualifier.

TABLE_SCHEMA

nvarchar(128)

Name of schema that contains the table.

Important noteImportant
Do not use INFORMATION_SCHEMA views to determine the schema of an object. The only reliable way to find the schema of a object is to query the sys.objects catalog view.

TABLE_NAME

nvarchar(128)

Table name.

COLUMN_NAME

nvarchar(128)

Column name.

ORDINAL_POSITION

int

Column ordinal position.