Thanks Pete very informative. I will have a look at that link today. Bob
On Apr 26, 2012, at 4:36 PM, Peter Haworth wrote: > Once again, this varies form db to db. Even sqlite3 can now allow readers > while the db is locked by setting the Write Ahead Locking pragma. > > For mySQL, there is a LOCK and an UNLOCK command which allow you to lock > individual tables for read and/or write access, as well as BEGIN and END, > which lock the whole database. There's a discussion on how LOCK/UNLOCK and > BEGIN/END work > here<http://dev.mysql.com/doc/refman/5.5/en/lock-tables-and-transactions.html> > but > I'd be inclined to use LOCK and UNLOCK rather than BEGIN/END for more > granularity unless you are carrying out some admin task for which you need > exclusive access to the whole db. > > I don't know anything about locking on other SQL implementations (yet!). > > Pete > lcSQL Software <http://www.lcsql.com> > > > > On Thu, Apr 26, 2012 at 3:22 PM, Bob Sneidar <[email protected]> wrote: > >> Oh thanks. I was aware that beginning a transaction made the database >> writable by only the client who began the transaction, but does it lock >> people out of reads as well? In the past I would manually lock a database >> while inserting records or before doing a transactional update, so that I >> could mark a particular master record as read only. I would then unlock the >> database and update as necessary to minimize the impact on other users. I >> did this only because that was what an old app called SBT written in Foxpro >> used to do, and that was all I knew at the time, but with transactions, >> maybe I don't need to worry about that anymore. >> >> Bob >> >> >> On Apr 26, 2012, at 3:14 PM, Peter Haworth wrote: >> >>> I think you're using mySQL Bob? If so, be aware that BEGIN and END are >>> also the means by which you lock the database. Doesn't matter too much >>> with sqlite because it's basically a single user db but with multi user >> dbs >>> like mySQL (actually just about any db other than sqlite), locking is a >>> whole other story! >>> >>> Pete >>> lcSQL Software <http://www.lcsql.com> >>> >>> >>> >>> On Thu, Apr 26, 2012 at 2:58 PM, Bob Sneidar <[email protected]> wrote: >>> >>>> Yes, transactions... good! I need to incorporate them into my app when I >>>> am ready to go into production (as if I will ever get to that point!). >>>> >>>> Bob >>>> >>>> >>>> On Apr 26, 2012, at 2:38 PM, Terry Judd wrote: >>>> >>>>> Wow, thanks Pete - I'll definitely give this method a try. >>>>> >>>>> Terry.. >>>> >>>> >>>> _______________________________________________ >>>> use-livecode mailing list >>>> [email protected] >>>> Please visit this url to subscribe, unsubscribe and manage your >>>> subscription preferences: >>>> http://lists.runrev.com/mailman/listinfo/use-livecode >>>> >>> _______________________________________________ >>> use-livecode mailing list >>> [email protected] >>> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >>> http://lists.runrev.com/mailman/listinfo/use-livecode >> >> >> _______________________________________________ >> use-livecode mailing list >> [email protected] >> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >> http://lists.runrev.com/mailman/listinfo/use-livecode >> > _______________________________________________ > use-livecode mailing list > [email protected] > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list [email protected] Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
