SQL - Find all blocking processes

DECLARE @tblWHO TABLE (SPID bigint, Status varchar(250), Login varchar(300), Hostname varchar(300), BlkBy varchar(100), DBName varchar(300), Command nvarchar(500)
					,CPUTime bigint, DiskIO bigint, LastBatch varchar(100), ProgramName varchar(300), SPID2 bigint, REQUESTID bigint)

INSERT INTO @tblWHO
	EXEC sp_who2

SELECT * FROM @tblWho WHERE SPID IN (SELECT TRY_CAST(BlkBy as bigint) FROM @tblWHO WHERE BlkBy NOT IN('  .','  .')) OR COALESCE(TRY_CAST(BlkBy as bigint),0) > 0

DECLARE @tblWHO TABLE (SPID bigint, Status varchar(250), Login varchar(300), Hostname varchar(300), BlkBy varchar(100), DBName varchar(300), Command nvarchar(500)
                    ,CPUTime bigint, DiskIO bigint, LastBatch varchar(100), ProgramName varchar(300), SPID2 bigint, REQUESTID bigint)

INSERT INTO @tblWHO
    EXEC sp_who2

SELECT tr.open_transaction_count, T.*, p.sql_handle, TEXT as Query FROM @tblWho T 
LEFT JOIN sys.sysprocesses p ON T.SPID = p.SPID
LEFT JOIN sys.dm_tran_session_transactions tr on t.SPID = tr.session_id
CROSS APPLY sys.dm_exec_sql_text(sql_handle)

DECLARE @tblWHO TABLE (SPID bigint, Status varchar(250), Login varchar(300), Hostname varchar(300), BlkBy varchar(100), DBName varchar(300), Command nvarchar(500)
                    ,CPUTime bigint, DiskIO bigint, LastBatch varchar(100), ProgramName varchar(300), SPID2 bigint, REQUESTID bigint)
 
INSERT INTO @tblWHO
    EXEC sp_who2
 
SELECT tr.open_transaction_count, T.*, p.sql_handle, TEXT as Query FROM @tblWho T
LEFT JOIN sys.sysprocesses p ON T.SPID = p.SPID
LEFT JOIN sys.dm_tran_session_transactions tr on t.SPID = tr.session_id
CROSS APPLY sys.dm_exec_sql_text(sql_handle)
WHERE
 T.SPID IN (
SELECT SPID FROM @tblWho WHERE SPID IN (SELECT TRY_CAST(BlkBy as bigint) FROM @tblWHO WHERE BlkBy NOT IN('  .','  .')) OR COALESCE(TRY_CAST(BlkBy as bigint),0) > 0
)