Aha! Now I understand what's going on. I have been completely missing the fact that everyone is trying to update the same table they're reading from. I know that's obvious to you guys, but I completely missed that subtle fact.
Everything makes sense now. Thanks for your patience. :) -Tom > -----Original Message----- > From: Martin Engelschalk [mailto:[EMAIL PROTECTED] > Sent: Thursday, May 12, 2005 9:53 AM > To: sqlite-users@sqlite.org > Subject: Re: [sqlite] database table is locked > > @Thomas Briggs, Jay Sprenckle > > I use the C Api described at http://www.sqlite.org/capi3ref.html. > > My code seemed to work with sqlite 3.0.7, but I cannot be too sure > because my project is in development. It would take some time > to check > with 3.0.7 > > My code worked roughly like this: > I created an update - Statement using compile(). > I created a query (simple select from one table) using compile() and > fetched the data using sqlite3_step() > When i found a record i needed to update, i bound 2 Variables using > sqlite3_bind_text() to the update statement, one of which was the > integer primary key. > The sqlite3_exec() failed with "database table is locked". > > This is a different thing to "database locked", i think. > > Martin > > Thomas Briggs schrieb: > > > This question seems to come up often, and I'm still confused as to > >what problems people are having. What APIs are you using to perform > >these steps? In particular, when you want to update a row, are you > >using a prepared query that is executed multiple times, or are you > >creating an SQL statement and executing that with > sqlite3_exec? Are you > >using 2.8 or 3.x? Maybe the confusion on my part is due to different > >database versions. > > > > I'm confused as to why executing a query would lock the database. > >The only thing I can think of is that the query required a > temp table, > >and the creation of that temp table led to the database being locked. > >The entire many readers/single writer concept makes no sense if > >executing any query locks the whole database. > > > > -Tom > > > > > > > >>-----Original Message----- > >>From: Thomas Fjellstrom [mailto:[EMAIL PROTECTED] > >>Sent: Thursday, May 12, 2005 7:10 AM > >>To: sqlite-users@sqlite.org > >>Subject: Re: [sqlite] database table is locked > >> > >>On May 12, 2005 04:59 am, Martin Engelschalk wrote: > >> > >> > >>>Hello, > >>> > >>>i open cursor on a table and retrieve rows from it. > >>>For every row i decide whether to update it. However, when > >>> > >>> > >>executing > >> > >> > >>>the update I get the error "database table is locked". > >>>My application is the only one working on the table. > >>>Is it illegal to update a table while selecting from it or > >>> > >>> > >>am i doing > >> > >> > >>>somethin wrong? > >>> > >>>Thanks, > >>>Martin > >>> > >>> > >>Yup. you'll have to scan for updates to make, then after the > >>scan, make the > >>updates. > >> > >>-- > >>Thomas Fjellstrom > >>[EMAIL PROTECTED] > >> > >> > >> >
