A query that calls sys.dm_exec_requests and pulls the statement text out of the request is a handy script for any DBA's toolbox. A simple version of the query performs a cross apply to dm_exec_sql_text and pulls out the request's TSQL statement-in-progress using the unicode character offsets.
This is simple enough and does a good job as a queryable sp_who2 and DBCC INPUTBUFFER replacement to an extent.
In an environment that suffers from frequent spells of query blocking, the ability to identify which query was leading the way becomes important in finding the query or queries to troubleshoot. Whether the end result of his query was a simple KILL command, and/or a walk down the hall to investigate the "business case" would be a situational decision.
I wanted a blocking chain - a list of all other spids that a session was blocking.
Here's a query that dumps the output of dm_exec_requests into a temporary table, then uses the XML PATH to conveniently transform the blocked_by list into a comma-delimited list in the row of the blocker. The sort order is the length of this comma-delimited list, putting the cause of a pileup right at the top.
Doing this in a temp table was necessary because the blocking_session_id is a highly volatile column. As a result, the output of this query is several ms behind "live". After a few executions, the spid hanging out at the top is easy enough to spot.
create table #ExecRequests ( id int IDENTITY(1,1) PRIMARY KEY ,session_id smallint not null ,sql_handle varbinary(64) ,statement_start_offset int ,statement_end_offset int ,plan_handle varbinary (64) ,blocking_session_id smallint ,wait_type nvarchar (120) ,[host_name] nvarchar(256) ,[program_name] nvarchar(256) ,blocking_these varchar(1000) null insert into #ExecRequests (session_id,request_id, start_time,status,command,sql_handle,statement_start_offset,statement_end_offset,plan_handle,database_id,user_id,blocking_session_id,wait_type,wait_time,cpu_time,tot_time,reads,writes,logical_reads,host_name, program_name) select r.session_id,request_id, start_time,r.status,command,sql_handle,statement_start_offset,statement_end_offset,plan_handle,r.database_id,user_id,blocking_session_id,wait_type,wait_time,r.cpu_time,r.total_elapsed_time,r.reads,r.writes,r.logical_reads,s.host_name, s.program_name from sys.dm_exec_requests r left outer join sys.dm_exec_sessions s on r.session_id = s.session_id and r.session_id > 35 --retrieve only user spids and r.session_id <> @@SPID --ignore myself update #ExecRequests set blocking_these = (select isnull(convert(varchar(5), er.session_id),'') + ', ' where er.blocking_session_id = isnull(#ExecRequests.session_id ,0) and er.blocking_session_id <> 0 r.session_id, r.host_name, r.program_name, r.status , 'LEN(Blocking)' = LEN(r.blocking_these) , blocked_by = r.blocking_session_id , DBName = db_name(r.database_id), r.command, r.wait_type, r.tot_time, r.wait_time, r.cpu_time, r.reads, r.writes, r.logical_reads , offsettext = CASE WHEN r.statement_start_offset = 0 and r.statement_end_offset= 0 THEN null SUBSTRING (est.[text], r.statement_start_offset/2 + 1, CASE WHEN r.statement_end_offset = -1 THEN LEN (CONVERT(nvarchar(max), est.[text])) ELSE r.statement_end_offset/2 - r.statement_start_offset/2 + 1 , r.statement_start_offset, r.statement_end_offset outer apply sys.dm_exec_sql_text (r.sql_handle) est order by LEN(r.blocking_these) desc, r.session_id asc 
