How to check if a table is locked in sql server

Question

I have a large report I am running on sql server. It takes several minutes to run. I don't want users clicking run twice. Since i wrap the whole procedure in a transaction, how do I check to see if the table is locked by a transaction? If so I would want to return an error message saying "report generating, please try again in a few minutes".

How can this be accomplished?

Answer 1

Better yet, consider sp_getapplock which is designed for this. Or use SET LOCK_TIMEOUT

Otherwise, you'd have to do something with sys.dm_tran_locks which I'd use only for DBA stuff: not for user defined concurrency.

Answer 2

You can try using sys.dm_tran_locks, wich returns information about currently active lock manager resources.

See this example

 SELECT 
     SessionID = s.Session_id,
     resource_type,   
     DatabaseName = DB_NAME(resource_database_id),
     request_mode,
     request_type,
     login_time,
     host_name,
     program_name,
     client_interface_name,
     login_name,
     nt_domain,
     nt_user_name,
     s.status,
     last_request_start_time,
     last_request_end_time,
     s.logical_reads,
     s.reads,
     request_status,
     request_owner_type,
     objectid,
     dbid,
     a.number,
     a.encrypted ,
     a.blocking_session_id,
     a.text       
 FROM   
     sys.dm_tran_locks l
     JOIN sys.dm_exec_sessions s ON l.request_session_id = s.session_id
     LEFT JOIN   
     (
         SELECT  *
         FROM    sys.dm_exec_requests r
         CROSS APPLY sys.dm_exec_sql_text(sql_handle)
     ) a ON s.session_id = a.session_id
 WHERE  
     s.session_id > 50

Bye.