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sp_change_users_login (Transact-SQL)

  • Article

Applies to: SQL Server

Maps an existing database user to a SQL Server login.

Important

This feature will be removed in a future version of SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. Use ALTER USER instead.

Transact-SQL syntax conventions

Syntax

sp_change_users_login
    [ @Action = ] 'Action'
    [ , [ @UserNamePattern = ] N'UserNamePattern' ]
    [ , [ @LoginName = ] N'LoginName' ]
    [ , [ @Password = ] N'Password' ]
[ ; ]

Arguments

[ @Action = ] 'Action'

Describes the action for the stored procedure to perform. @Action is varchar(10), with no default, and can have one of the following values.

Value Description
Auto_Fix Links a user entry in the sys.database_principals system catalog view in the current database to a SQL Server login of the same name. If a login with the same name doesn't exist, one is created. Examine the result from the Auto_Fix statement, to confirm that the correct link is in fact made. Avoid using Auto_Fix in security-sensitive situations.

When you use Auto_Fix, you must specify @UserNamePattern and @Password if the login doesn't already exist, otherwise you must specify @UserNamePattern but @Password is ignored. @LoginName must be NULL. @UserNamePattern must be a valid user in the current database. The login can't have another user mapped to it.
Report Lists the users and corresponding security identifiers (SID) in the current database that aren't linked to any login. @UserNamePattern, @LoginName, and @Password must be NULL or not specified.

To replace the report option with a query using the system tables, compare the entries in sys.server_principals with the entries in sys.database_principals.
Update_One Links the specified @UserNamePattern in the current database to an existing SQL Server @LoginName. @UserNamePattern and @LoginName must be specified. @Password must be NULL or not specified.

[ @UserNamePattern = ] N'UserNamePattern'

The name of a user in the current database. @UserNamePattern is sysname, with a default of NULL.

[ @LoginName = ] N'LoginName'

The name of a SQL Server login. @LoginName is sysname, with a default of NULL.

[ @Password = ] N'Password'

The password assigned to a new SQL Server login that is created by specifying Auto_Fix. @Password is sysname, and can't be NULL. If a matching login already exists, the user and login are mapped and @Password is ignored. If a matching login doesn't exist, sp_change_users_login creates a new SQL Server login and assigns @Password as the password for the new login.

Important

Always use a strong password.

Return code values

0 (success) or 1 (failure).

Result set

Column name Data type Description
UserName sysname Database user name.
UserSID varbinary(85) User's security identifier.

Remarks

Use sp_change_users_login to link a database user in the current database with a SQL Server login. If the login for a user changes, use sp_change_users_login to link the user to the new login without losing user permissions. The new @LoginName can't be sa, and the @UserNamePattern can't be dbo, guest, or an INFORMATION_SCHEMA user.

sp_change_users_login can't be used to map database users to Windows-level principals, certificates, or asymmetric keys.

sp_change_users_login can't be used with a SQL Server login created from a Windows principal or with a user created by using CREATE USER WITHOUT LOGIN.

sp_change_users_login can't be executed within a user-defined transaction.

Permissions

Requires membership in the db_owner fixed database role. Only members of the sysadmin fixed server role can specify the Auto_Fix option.

Examples

The code samples in this article use the AdventureWorks2022 or AdventureWorksDW2022 sample database, which you can download from the Microsoft SQL Server Samples and Community Projects home page.

A. Show a report of the current user to login mappings

The following example produces a report of the users in the current database and their security identifiers (SIDs).

EXEC sp_change_users_login 'Report';

B. Map a database user to a new SQL Server login

In the following example, a database user is associated with a new SQL Server login. Database user MB-Sales, which at first is mapped to another login, is remapped to login MaryB.

--Create the new login.
CREATE LOGIN MaryB WITH PASSWORD = '982734snfdHHkjj3';
GO
--Map database user MB-Sales to login MaryB.
USE AdventureWorks2022;
GO
EXEC sp_change_users_login 'Update_One', 'MB-Sales', 'MaryB';
GO

C. Automatically map a user to a login, and create a new login if necessary

The following example shows how to use Auto_Fix to map an existing user to a login of the same name, or to create the SQL Server login Mary that's the password B3r12-3x$098f6 if the login Mary doesn't exist.

USE AdventureWorks2022;
GO
EXEC sp_change_users_login 'Auto_Fix', 'Mary', NULL, 'B3r12-3x$098f6';
GO

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