Last Query for All Open Connections (source):
SELECT *
FROM sys.dm_exec_requests er
CROSS APPLY sys.dm_exec_sql_text(er.sql_handle) AS t
Number of Open Connections (source):
SELECT
DB_NAME(dbid) as DBName,
COUNT(dbid) as NumberOfConnections,
loginame as LoginName
FROM
sys.sysprocesses
WHERE
dbid > 0
GROUP BY
dbid, loginame
Running Queries (Source):
SELECT sqltext.TEXT, req.session_id, req.status, req.command, req.cpu_time, req.total_elapsed_time
FROM sys.dm_exec_requests req
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS sqltext
Kill Query (Source)
Kill {id}