USER_ID (Transact-SQL)

Alt
09/03/2024

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance

Returns the identification number for a database user.

Tábhachtach

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 DATABASE_PRINCIPAL_ID instead.

Transact-SQL syntax conventions

Syntax

syntaxsql

USER_ID ( [ 'user' ] )

Arguments

user
Is the username to be used. user is nchar. If a char value is specified, it is implicitly converted to nchar. The parentheses are required.

Return Types

int

Remarks

When user is omitted, the current user is assumed. If the parameter contains the word NULL will return NULL.When USER_ID is called after EXECUTE AS, USER_ID will return the ID of the impersonated context.

When a Windows principal that is not mapped to a specific database user accesses a database by way of membership in a group, USER_ID returns 0 (the ID of public). If such a principal creates an object without specifying a schema, SQL Server will create an implicit user and schema mapped to the Windows principal. The user created in such cases cannot be used to connect to the database. Calls to USER_ID by a Windows principal mapped to an implicit user will return the ID of the implicit user.

USER_ID can be used in a select list, in a WHERE clause, and anywhere an expression is allowed. For more information, see Expressions (Transact-SQL).

Examples

The following example returns the identification number for the AdventureWorks2022 user Harold.

SQL

USE AdventureWorks2022;  
SELECT USER_ID('Harold');  
GO

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