CURRENT_USER() Function in SQL Server

CURRENT_USER() function :
This function in SQL Server is used to return the current user’s name in the database of SQL Server in use.

Features :

• This function is used to find the current user’s name.
• This function comes under Advanced Functions.
• This function doesn’t accept any parameter.

Syntax :

CURRENT_USER

Parameter : This method does not accept any parameter.

Returns : It returns the current user’s name in the database of SQL Server which is in use.

Example-1 :
Using CURRENT_USER () function and getting the current user’s name.

SELECT CURRENT_USER;

Output :

nidhi

Example-2 :
Using CURRENT_USER as a default value in the below example and getting the output.

CREATE TABLE user01 (  
user_id int IDENTITY(100, 2) NOT NULL,
customer_id int NOT NULL,
user_name char(50) NOT NULL DEFAULT CURRENT_USER
); 

 Inserting values in the table –

INSERT user01(customer_id)  
VALUES (101), (102);

Displaying the contents of the table –

SELECT * 
FROM user01;  

Output :

	user_id	customer_id	user_name
1	100	101	nidhi
2	101	102	nidhi

Here, firstly you need to create a table then insert values into it then generate the required output using CURRENT_USER function as a default value.

Note: For running above code use SQL server compiler, you can also use an online compiler.

Example-3 :
Using CURRENT_USER () function and impersonating user ‘Geek’.

SELECT CURRENT_USER;  
EXECUTE AS USER = 'Geek';  
SELECT CURRENT_USER;   

Output :

nidhi
Geek

Here, we are impersonating user as ‘Geek’, then calling CURRENT_USER function to get the current user’s name.

Example-4 :
Using CURRENT_USER () function for impersonating user ‘Geek’ then again reverting the code to get the previous current user.

SELECT CURRENT_USER;  
EXECUTE AS USER = 'Geek';  
SELECT CURRENT_USER;   
REVERT;
SELECT CURRENT_USER;

Output :

nidhi
Geek
nidhi

Application :

• This function is used to find the current user’s name in the database of the SQL server.