sys-masked-columns-transact-sql.md

title	description	author	ms.author	ms.date	ms.service	ms.subservice	ms.topic	f1_keywords	helpviewer_keywords	dev_langs	monikerRange
sys.masked_columns (Transact-SQL)	sys.masked_columns (Transact-SQL)	rwestMSFT	randolphwest	05/25/2021	sql	system-objects	reference	sys.masked_columns masked_columns_tsql sys.masked_columns_tsql masked_columns	sys.masked_columns catalog view	TSQL	=azuresqldb-current||>=sql-server-2016||>=sql-server-linux-2017||=azuresqldb-mi-current

sys.masked_columns (Transact-SQL)

[!INCLUDE sqlserver2016-asdb-asdbmi]

Use the sys.masked_columns view to query for table-columns that have a dynamic data masking function applied to them. This view inherits from the sys.columns view. It returns all columns in the sys.columns view, plus the is_masked and masking_function columns, indicating if the column is masked, and if so, what masking function is defined. This view only shows the columns on which there is a masking function applied.

Column name	Data type	Description
object_id	int	ID of the object to which this column belongs.
name	sysname	Name of the column. Is unique within the object.
column_id	int	ID of the column. Is unique within the object. Column IDs might not be sequential.
sys.masked_columns returns many more columns inherited from sys.columns.	various	See sys.columns (Transact-SQL) for more column definitions.
is_masked	bit	Indicates if the column is masked. 1 indicates masked.
masking_function	nvarchar(4000)	The masking function for the column.
generated_always_type	tinyint	Applies to: [!INCLUDEsssql16-md] and later, [!INCLUDEssSDS_md]. 7, 8, 9, 10 only applies to [!INCLUDEssSDS_md]. Identifies when the column value is generated (will always be 0 for columns in system tables): 0 = NOT_APPLICABLE 1 = AS_ROW_START 2 = AS_ROW_END 7 = AS_TRANSACTION_ID_START 8 = AS_TRANSACTION_ID_END 9 = AS_SEQUENCE_NUMBER_START 10 = AS_SEQUENCE_NUMBER_END For more information, see Temporal Tables (Relational databases).

Permissions

This view returns information about tables where the user has some sort of permission on the table or if the user has the VIEW ANY DEFINITION permission.

Example

The following query joins sys.masked_columns to sys.tables to return information about all masked columns.

SELECT tbl.name as table_name, c.name AS column_name, c.is_masked, c.masking_function  
FROM sys.masked_columns AS c  
JOIN sys.tables AS tbl   
    ON c.object_id = tbl.object_id  
WHERE is_masked = 1;  

See Also

Dynamic Data Masking
sys.columns (Transact-SQL)