Re: Multi user lock
Locking a table is usually done when a transaction or series of transactions is taking place in order to synchronize the transactions. If you wish to lock a table so that only one user can update it, then you would need to create a separate mechanism that relies on your web server / browser.
The trouble you may run into this is a time out period. As web interactions are stateless, the web server will not know if the end user that locked the table is in fact timed out, disconnected, or left the page. This then would leave the table locked indefinitely, or until the user returned to unlock it.
With that said, you would create a new table that lists the tables and their locked status, when locked, and who locked them. Your page would query this table and present the data accordingly - provide an editable table or a non-editable table.
Hope this helps,