suser-sname-transact-sql.md

title	SUSER_SNAME (Transact-SQL) | Microsoft Docs
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ms.date	07/29/2017
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helpviewer_keywords	security identification names [SQL Server] logins [SQL Server], users SIDs [SQL Server] SUSER_SNAME function users [SQL Server], logins logins [SQL Server], names IDs [SQL Server], logins identification numbers [SQL Server], logins names [SQL Server], logins
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SUSER_SNAME (Transact-SQL)

[!INCLUDEtsql-appliesto-ss2008-all_md]

Returns the login name associated with a security identification number (SID).

Transact-SQL Syntax Conventions

Syntax

-- Syntax for SQL Server, Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse  
  
SUSER_SNAME ( [ server_user_sid ] )   

Arguments

server_user_sid
Applies to: [!INCLUDEssKatmai] through [!INCLUDEssCurrent]

Is the optional login security identification number. server_user_sid is varbinary(85). server_user_sid can be the security identification number of any [!INCLUDEssNoVersion] login or [!INCLUDEmsCoName] Windows user or group. If server_user_sid is not specified, information about the current user is returned. If the parameter contains the word NULL will return NULL.

Return Types

nvarchar(128)

Remarks

SUSER_SNAME can be used as a DEFAULT constraint in either ALTER TABLE or CREATE TABLE. SUSER_SNAME can be used in a select list, in a WHERE clause, and anywhere an expression is allowed. SUSER_SNAME must always be followed by parentheses, even if no parameter is specified.

When called without an argument, SUSER_SNAME returns the name of the current security context. When called without an argument within a batch that has switched context by using EXECUTE AS, SUSER_SNAME returns the name of the impersonated context. When called from an impersonated context, ORIGINAL_LOGIN returns the name of the original context.

[!INCLUDEssSDSfull] Remarks

SUSER_NAME always return the login name for the current security context.

The SUSER_SNAME statement does not support execution using an impersonated security context through EXECUTE AS.

Examples

A. Using SUSER_SNAME

The following example returns the login name for the current security context.

SELECT SUSER_SNAME();  
GO  

B. Using SUSER_SNAME with a Windows user security ID

The following example returns the login name associated with a Windows security identification number.

Applies to: [!INCLUDEssKatmai] through [!INCLUDEssCurrent]

SELECT SUSER_SNAME(0x010500000000000515000000a065cf7e784b9b5fe77c87705a2e0000);  
GO  

C. Using SUSER_SNAME as a DEFAULT constraint

The following example uses SUSER_SNAME as a DEFAULT constraint in a CREATE TABLE statement.

USE AdventureWorks2012;  
GO  
CREATE TABLE sname_example  
(  
login_sname sysname DEFAULT SUSER_SNAME(),  
employee_id uniqueidentifier DEFAULT NEWID(),  
login_date  datetime DEFAULT GETDATE()  
);   
GO  
INSERT sname_example DEFAULT VALUES;  
GO  

D. Calling SUSER_SNAME in combination with EXECUTE AS

This example shows the behavior of SUSER_SNAME when called from an impersonated context.

Applies to: [!INCLUDEssKatmai] through [!INCLUDEssCurrent]

SELECT SUSER_SNAME();  
GO  
EXECUTE AS LOGIN = 'WanidaBenShoof';  
SELECT SUSER_SNAME();  
REVERT;  
GO  
SELECT SUSER_SNAME();  
GO  
  

Here is the result.

sa

WanidaBenShoof

sa

Examples: [!INCLUDEssSDWfull] and [!INCLUDEssPDW]

E. Using SUSER_SNAME

The following example returns the login name for the security identification number with a value of 0x01.

SELECT SUSER_SNAME(0x01);  
GO  

F. Returning the Current Login

The following example returns the login name of the current login.

SELECT SUSER_SNAME() AS CurrentLogin;  
GO  

See Also

SUSER_SID (Transact-SQL)
Principals (Database Engine)
sys.server_principals (Transact-SQL)
EXECUTE AS (Transact-SQL)