Applies to: SQL Server (all supported versions) Azure SQL Managed Instance Azure Synapse Analytics (serverless SQL pool only)
Returns the login identification name of the user.
SUSER_NAME ( [ server_user_id ] )
To view Transact-SQL syntax for SQL Server 2014 and earlier, see Previous versions documentation.
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 SQL Server login or Microsoft Windows user or group that has permission to connect to an instance of SQL Server. When server_user_id isn't specified, the login identification name for the current user is returned. If the parameter contains the word NULL, it will return NULL.
In SQL Server 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. Use parentheses after SUSER_NAME, even if no parameter is specified.
Although the SUSER_NAME function is supported on Azure SQL Database, using Execute as with SUSER_NAME is not supported on Azure SQL Database.
The following example returns the login identification name of the user with a login identification number of