How to see active SQL Server connections for database

Using simple select statements

SELECT 
    DB_NAME(dbid) as DBName, 
    COUNT(dbid) as NumberOfConnections,
    loginame as LoginName
FROM
    sys.sysprocesses
WHERE 
    dbid > 0 AND DB_NAME(dbid) LIkE '{DBNAME}'
GROUP BY 
    dbid, loginame
;

or using stored procedure

sp_who or sp_who