SQL Lookup logged in users

exec sp_who2


select d.name, d.dbid, spid, login_time, nt_domain, nt_username, loginame
  from sysprocesses p inner join sysdatabases d on p.dbid = d.dbid
 where d.name = 'DBNAME'

SQL Free up busy database resources

use master
ALTER DATABASE im_test_restore SET SINGLE_USER WITH ROLLBACK IMMEDIATE
  
use im_test_restore;
go
 
checkpoint;
go
 
use master;

go
  
ALTER DATABASE im_test_restore SET MULTI_USER

Rename a busy database in SQL Server

use master
ALTER DATABASE YourDBName SET SINGLE_USER WITH ROLLBACK IMMEDIATE
 
use YourDBName;
go

checkpoint;
go

use master;
go

alter database YourDBName modify name = YourDBNameNewName;
go
 
ALTER DATABASE YourDBName SET MULTI_USER