drop-column-master-key-transact-sql.md

title	DROP COLUMN MASTER KEY (Transact-SQL) | Microsoft Docs
ms.custom
ms.date	04/20/2016
ms.prod	sql
ms.prod_service	database-engine, sql-database
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ms.technology	t-sql
ms.topic	language-reference
f1_keywords	DROP COLUMN MASTER KEY DROP_COLUMN_MASTER_KEY_TSQL DROP COLUMN MASTER DROP_COLUMN_MASTER_TSQL
dev_langs	TSQL
helpviewer_keywords	sys.column_master_keys catalog view
ms.assetid	fd5e77c8-a3ae-4795-bb46-b322c0500041
author	VanMSFT
ms.author	vanto

DROP COLUMN MASTER KEY (Transact-SQL)

[!INCLUDEtsql-appliesto-ss2016-asdb-xxxx-xxx-md]

Drops a column master key from a database. This is a metadata operation.

Transact-SQL Syntax Conventions

Syntax

  
DROP COLUMN MASTER KEY key_name;  

Arguments

key_name
The name of the column master key.

Remarks

The column master key can only be dropped if there are no column encryption key values encrypted with the column master key. To drop column encryption key values, use the DROP COLUMN ENCRYPTION KEY statement.

Permissions

Requires ALTER ANY COLUMN MASTER KEY permission on the database.

Examples

A. Dropping a column master key

The following example drops a column master key called MyCMK.

DROP COLUMN MASTER KEY MyCMK;  
GO  

See Also

CREATE COLUMN MASTER KEY (Transact-SQL)
CREATE COLUMN ENCRYPTION KEY (Transact-SQL)
DROP COLUMN ENCRYPTION KEY (Transact-SQL)
Always Encrypted (Database Engine)
sys.column_master_keys (Transact-SQL)