Kill all connections to SQL Server database -- fast

What's the fastest way to kill all database connections?  Properly, I should say... without pulling the cord on the server.

I'm glad you asked! 😉  The easiest/fastest way that I am aware of is to set the database into SINGLE_USER.  This will sever all active connections to the database aside from your own.  Like this: 

-- kill all connections to a database

USE master;

ALTER DATABASE SSISDB -- change to your dbname

SET SINGLE_USER

WITH ROLLBACK IMMEDIATE; 

When you've done your thing and you're ready to let them back in, you'll set it back to MULTI_USER, like this:

-- set it back into multi user

USE master;

ALTER DATABASE SSISDB -- change to your dbname

SET MULTI_USER;

Easy peasy.

You could also use a cursor to go through all active processes in the database, killing them sequentially... but, I don't often recommend the cursor method, if it can be avoided.