Hi. Thanks for the suggestions. At the moment, im very new to using SQLite, so I haven't done anything advanced with its usage in my program. I pretty much read through the 5 minute intro using C/C++, looked at a few of the API docs, and then proceeded to use it from that information. So I've just modified the 5-minute intro to my needs, and used some of the other API's, but nothing too advanced.
However, when searching for the problem I was receiving, I saw a trac/commit/wiki and page regarding the places that would cause locking issues. As far as I understand, I should be able to do a select on a table that is currently being updated without causing any locking issues right? As it currently stands, I did modify my program to deal with the SQLITE_BUSY returns, and I see now that im getting database is locked problems when doing a select now. Without debugging the issue too deeply, im guessing that the "Database is locked" problem is now being caused by a select while another program is updating the table. However, this shouldn't be an issue anymore according to the page : http://www.sqlite.org/cvstrac/wiki?p=DatabaseIsLocked If im wrong, or misunderstood or misread something, then please let me know. Also if you have further suggestions as to getting around this problem, I am happy to try anything. Thanks for any further help. Regards /Cole -----Original Message----- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Edzard Pasma Sent: 19 July 2009 11:50 AM To: kennethinbox-sql...@yahoo.com; General Discussion of SQLite Database Cc: sqlite-users@sqlite.org Subject: Re: [sqlite] Multiple Writers and Database is Locked Problems I'd also make sure that all read-cursors are finished before starting a transaction. Or, take the exclusive lock already before the queries (possibly that is what was meant) --- kennethinbox-sql...@yahoo.com wrote: >From: Ken <kennethinbox-sql...@yahoo.com> >To: General Discussion of SQLite Database <sqlite-users@sqlite.org> >Subject: Re: [sqlite] Multiple Writers and Database is Locked Problems >Date: Sat, 18 Jul 2009 12:29:33 -0700 (PDT) > > >I like to start each of my transactions with a "Begin Immediate" >that way the database file is locked at that point. And its >relatively simple to test for the DB locked at that stage and >handle waiting or returning an error. > >HTH > >--- On Fri, 7/17/09, Cole <c...@opteqint.net> wrote: > >> From: Cole <c...@opteqint.net> >> Subject: [sqlite] Multiple Writers and Database is Locked Problems >> To: sqlite-users@sqlite.org >> Date: Friday, July 17, 2009, 6:38 AM >> Hi. >> >> Im hoping someone might be able to help me with the >> problems im having, or >> suggest a better method of doing what im trying to achieve. >> Currently im >> using sqlite3 3.6.10. I don't mind updating or downgrading >> it if needed. >> >> I have a program that I run multiple instances of. When >> they start, they >> parse the config file, and open a connection to each >> database that is >> listed. Each database only has a single table in it. They >> then receive >> requests, do a select on the database, parse the returned >> data, modify the >> data, then update the data to the database. However, I am >> running into the >> "database is locked" error when trying to update the >> database. I fully >> understand that 2 or more instances might be trying to >> update the same >> table, but is this the only reason this might happen now? >> Or are there also >> other scenarios where this might happen? >> >> Ive searched the mailing list and I see that you mention >> using random seed >> and time to handle the SQLITE_BUSY return value, and then >> trying to perform >> the update again. I was perhaps wondering if there are any >> other suggestions >> for dealing with this scenario where there might be >> multiple writers to the >> same database at the same time? >> >> Regards >> /Cole _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
