--- title: "ALTER LOGIN (Transact-SQL) | Microsoft Docs" ms.custom: "" ms.date: "05/01/2017" ms.prod: "sql-non-specified" ms.reviewer: "" ms.suite: "" ms.technology: - "database-engine" ms.tgt_pltfrm: "" ms.topic: "language-reference" f1_keywords: - "ALTER_LOGIN_TSQL" - "ALTER LOGIN" dev_langs: - "TSQL" helpviewer_keywords: - "ALTER LOGIN statement" - "change password" - "mapping logins [SQL Server]" - "logins [SQL Server], modifying" - "passwords [SQL Server], modifying" - "names [SQL Server], logins" - "modifying login accounts" ms.assetid: e247b84e-c99e-4af8-8b50-57586e1cb1c5 caps.latest.revision: 68 author: "BYHAM" ms.author: "rickbyh" manager: "jhubbard" --- # ALTER LOGIN (Transact-SQL) [!INCLUDE[tsql-appliesto-ss2008-all_md](../../includes/tsql-appliesto-ss2008-all-md.md)] Changes the properties of a [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] login account. ![Topic link icon](../../database-engine/configure-windows/media/topic-link.gif "Topic link icon") [Transact-SQL Syntax Conventions](../../t-sql/language-elements/transact-sql-syntax-conventions-transact-sql.md) ## Syntax ``` -- Syntax for SQL Server ALTER LOGIN login_name { | WITH [ ,... ] | } [;] ::= ENABLE | DISABLE ::= PASSWORD = 'password' | hashed_password HASHED [ OLD_PASSWORD = 'oldpassword' | [ ] ] | DEFAULT_DATABASE = database | DEFAULT_LANGUAGE = language | NAME = login_name | CHECK_POLICY = { ON | OFF } | CHECK_EXPIRATION = { ON | OFF } | CREDENTIAL = credential_name | NO CREDENTIAL ::= MUST_CHANGE | UNLOCK ::= ADD CREDENTIAL credential_name | DROP CREDENTIAL credential_name ``` ``` -- Syntax for Azure SQL Database ALTER LOGIN login_name { | WITH [ ,.. .n ] } [;] ::= ENABLE | DISABLE ::= PASSWORD ='password' [ OLD_PASSWORD ='oldpassword' ] | NAME = login_name ``` ``` -- Syntax for Azure SQL Data Warehouse and Parallel Data Warehouse ALTER LOGIN login_name { | WITH [ ,... ] } ::=ENABLE | DISABLE ::= PASSWORD ='password' [ OLD_PASSWORD ='oldpassword' | [ ] ] | NAME = login_name | CHECK_POLICY = { ON | OFF } | CHECK_EXPIRATION = { ON | OFF } ::= MUST_CHANGE | UNLOCK ``` ## Arguments *login_name* Specifies the name of the [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] login that is being changed. Domain logins must be enclosed in brackets in the format [domain\user]. ENABLE | DISABLE Enables or disables this login. Disabling a login does not affect the behavior of logins that are already connected. (Use the `KILL` statement to terminate an existing connections.) Disabled logins retain their permissions and can still be impersonated. PASSWORD **='***password***'** Applies only to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] logins. Specifies the password for the login that is being changed. Passwords are case-sensitive. Continuously active connections to SQL Database require reauthorization (performed by the Database Engine) at least every 10 hours. The Database Engine attempts reauthorization using the originally submitted password and no user input is required. For performance reasons, when a password is reset in SQL Database, the connection will not be re-authenticated, even if the connection is reset due to connection pooling. This is different from the behavior of on-premises SQL Server. If the password has been changed since the connection was initially authorized, the connection must be terminated and a new connection made using the new password. A user with the KILL DATABASE CONNECTION permission can explicitly terminate a connection to SQL Database by using the KILL command. For more information, see [KILL (Transact-SQL)](../../t-sql/language-elements/kill-transact-sql.md). PASSWORD **=***hashed_password* **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Applies to the HASHED keyword only. Specifies the hashed value of the password for the login that is being created. > [!IMPORTANT] > When a login (or a contained database user) connects and is authenticated, the connection caches identity information about the login. For a Windows Authentication login, this includes information about membership in Windows groups. The identity of the login remains authenticated as long as the connection is maintained. To force changes in the identity, such as a password reset or change in Windows group membership, the login must logoff from the authentication authority (Windows or [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)]), and log in again. A member of the **sysadmin** fixed server role or any login with the **ALTER ANY CONNECTION** permission can use the **KILL** command to end a connection and force a login to reconnect. [!INCLUDE[ssManStudioFull](../../includes/ssmanstudiofull-md.md)] can reuse connection information when opening multiple connections to Object Explorer and Query Editor windows. Close all connections to force reconnection. HASHED **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Applies to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] logins only. Specifies that the password entered after the PASSWORD argument is already hashed. If this option is not selected, the password is hashed before being stored in the database. This option should only be used for login synchronization between two servers. Do not use the HASHED option to routinely change passwords. OLD_PASSWORD **='***oldpassword***'** Applies only to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] logins. The current password of the login to which a new password will be assigned. Passwords are case-sensitive. MUST_CHANGE **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Applies only to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] logins. If this option is included, [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] will prompt for an updated password the first time the altered login is used. DEFAULT_DATABASE **=***database* **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Specifies a default database to be assigned to the login. DEFAULT_LANGUAGE **=***language* **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Specifies a default language to be assigned to the login. The default language for all SQL Database logins is English and cannot be changed. The default language of the `sa` login on [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] on Linux, is English but it can be changed. NAME = *login_name* The new name of the login that is being renamed. If this is a Windows login, the SID of the Windows principal corresponding to the new name must match the SID associated with the login in [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)]. The new name of a [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] login cannot contain a backslash character (\\). CHECK_EXPIRATION = { ON | **OFF** } **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Applies only to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] logins. Specifies whether password expiration policy should be enforced on this login. The default value is OFF. CHECK_POLICY **=** { **ON** | OFF } **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Applies only to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] logins. Specifies that the Windows password policies of the computer on which [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] is running should be enforced on this login. The default value is ON. CREDENTIAL = *credential_name* **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. The name of a credential to be mapped to a [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] login. The credential must already exist in the server. For more information see [Credentials (Database Engine)](../../relational-databases/security/authentication-access/credentials-database-engine.md). A credential cannot be mapped to the sa login. NO CREDENTIAL **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Removes any existing mapping of the login to a server credential. For more information see [Credentials (Database Engine)](../../relational-databases/security/authentication-access/credentials-database-engine.md). UNLOCK **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Applies only to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] logins. Specifies that a login that is locked out should be unlocked. ADD CREDENTIAL **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Adds an Extensible Key Management (EKM) provider credential to the login. For more information, see [Extensible Key Management (EKM)](../../relational-databases/security/encryption/extensible-key-management-ekm.md). DROP CREDENTIAL **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. Removes an Extensible Key Management (EKM) provider credential from the login. For more information see [Extensible Key Management (EKM)](../../relational-databases/security/encryption/extensible-key-management-ekm.md). ## Remarks When CHECK_POLICY is set to ON, the HASHED argument cannot be used. When CHECK_POLICY is changed to ON, the following behavior occurs: - The password history is initialized with the value of the current password hash. When CHECK_POLICY is changed to OFF, the following behavior occurs: - CHECK_EXPIRATION is also set to OFF. - The password history is cleared. - The value of *lockout_time* is reset. If MUST_CHANGE is specified, CHECK_EXPIRATION and CHECK_POLICY must be set to ON. Otherwise, the statement will fail. If CHECK_POLICY is set to OFF, CHECK_EXPIRATION cannot be set to ON. An ALTER LOGIN statement that has this combination of options will fail. You cannot use ALTER_LOGIN with the DISABLE argument to deny access to a Windows group. For example, ALTER_LOGIN [*domain\group*] DISABLE will return the following error message: "Msg 15151, Level 16, State 1, Line 1 "Cannot alter the login '*Domain\Group*', because it does not exist or you do not have permission." This is by design. In [!INCLUDE[ssSDS](../../includes/sssds-md.md)], login data required to authenticate a connection and server-level firewall rules are temporarily cached in each database. This cache is periodically refreshed. To force a refresh of the authentication cache and make sure that a database has the latest version of the logins table, execute [DBCC FLUSHAUTHCACHE (Transact-SQL)](../../t-sql/database-console-commands/dbcc-flushauthcache-transact-sql.md). ## Permissions Requires ALTER ANY LOGIN permission. If the CREDENTIAL option is used, also requires ALTER ANY CREDENTIAL permission. If the login that is being changed is a member of the **sysadmin** fixed server role or a grantee of CONTROL SERVER permission, also requires CONTROL SERVER permission when making the following changes: - Resetting the password without supplying the old password. - Enabling MUST_CHANGE, CHECK_POLICY, or CHECK_EXPIRATION. - Changing the login name. - Enabling or disabling the login. - Mapping the login to a different credential. A principal can change the password, default language, and default database for its own login. ## Examples ### A. Enabling a disabled login The following example enables the login `Mary5`. ```tsql ALTER LOGIN Mary5 ENABLE; ``` ### B. Changing the password of a login The following example changes the password of login `Mary5` to a strong password. ```tsql ALTER LOGIN Mary5 WITH PASSWORD = ''; ``` ### C. Changing the name of a login The following example changes the name of login `Mary5` to `John2`. ```tsql ALTER LOGIN Mary5 WITH NAME = John2; ``` ### D. Mapping a login to a credential The following example maps the login `John2` to the credential `Custodian04`. ```tsql ALTER LOGIN John2 WITH CREDENTIAL = Custodian04; ``` ### E. Mapping a login to an Extensible Key Management credential The following example maps the login `Mary5` to the EKM credential `EKMProvider1`. **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. ```tsql ALTER LOGIN Mary5 ADD CREDENTIAL EKMProvider1; GO ``` ### F. Unlocking a login To unlock a [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] login, execute the following statement, replacing **** with the desired account password. ```tsql ALTER LOGIN [Mary5] WITH PASSWORD = '****' UNLOCK ; GO ``` To unlock a login without changing the password, turn the check policy off and then on again. ```tsql ALTER LOGIN [Mary5] WITH CHECK_POLICY = OFF; ALTER LOGIN [Mary5] WITH CHECK_POLICY = ON; GO ``` ### G. Changing the password of a login using HASHED The following example changes the password of the `TestUser` login to an already hashed value. **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)]. ```tsql ALTER LOGIN TestUser WITH PASSWORD = 0x01000CF35567C60BFB41EBDE4CF700A985A13D773D6B45B90900 HASHED ; GO ``` ## See Also [Credentials (Database Engine)](../../relational-databases/security/authentication-access/credentials-database-engine.md) [CREATE LOGIN (Transact-SQL)](../../t-sql/statements/create-login-transact-sql.md) [DROP LOGIN (Transact-SQL)](../../t-sql/statements/drop-login-transact-sql.md) [CREATE CREDENTIAL (Transact-SQL)](../../t-sql/statements/create-credential-transact-sql.md) [EVENTDATA (Transact-SQL)](../../t-sql/functions/eventdata-transact-sql.md) [Extensible Key Management (EKM)](../../relational-databases/security/encryption/extensible-key-management-ekm.md)