title: "SUSER_NAME (Transact-SQL) | Microsoft Docs" ms.custom: "" ms.date: "03/14/2017" ms.prod: sql ms.prod_service: "sql-data-warehouse, sql-database" ms.reviewer: "" ms.suite: "sql" ms.technology: t-sql ms.tgt_pltfrm: "" ms.topic: "language-reference" f1_keywords:
- "SUSER_NAME"
- "SUSER_NAME_TSQL" dev_langs:
- "TSQL" helpviewer_keywords:
- "security identification names [SQL Server]"
- "logins [SQL Server], users"
- "identification names for logins [SQL Server]"
- "users [SQL Server], logins"
- "SUSER_NAME function"
- "logins [SQL Server], names"
- "names [SQL Server], logins" ms.assetid: ae598d9f-9baa-49b8-b1c1-042854206de4 caps.latest.revision: 29 author: MashaMSFT ms.author: mathoma manager: craigg monikerRange: "=azure-sqldw-latest||>=sql-server-2016||=sqlallproducts-allversions||>=sql-server-linux-2017"
[!INCLUDEtsql-appliesto-ss2008-xxxx-asdw-xxx-md]
Returns the login identification name of the user.
Transact-SQL Syntax Conventions
SUSER_NAME ( [ server_user_id ] )
server_user_id
Is the login identification number of the user. server_user_id, which is optional, is int. server_user_id can be the login identification number of any [!INCLUDEssNoVersion] login or [!INCLUDEmsCoName] Windows user or group that has permission to connect to an instance of [!INCLUDEssNoVersion]. If server_user_id is not specified, the login identification name for the current user is returned. If the parameter contains the word NULL will return NULL.
nvarchar(128)
In [!INCLUDEssNoVersion] version 7.0, the security identification number (SID) replaced the server user identification number (SUID).
SUSER_NAME returns a login name only for a login that has an entry in the syslogins system table.
SUSER_NAME can be used in a select list, in a WHERE clause, and anywhere an expression is allowed, and must always be followed by parentheses, even if no parameter is specified.
The following example returns the login identification name of the user with a login identification number of 1.
SELECT SUSER_NAME(1);