current_user function
Applies to: 
Databricks SQL Databricks Runtime 10.4 LTS and above
Returns the user executing the statement. current_user is an alias for user.
note
The SQL standard differentiates between CURRENT_USER and SESSION_USER.
In Databricks SQL and Databricks Runtime 14.1 and above you should use SESSION_USER instead of CURRENT_USER or USER.
Syntax
current_user()
Arguments
This function takes no arguments.
Returns
A STRING.
The braces are optional.
Examples
SQL
> SELECT current_user();
user1
> SELECT current_user;
user1