What did your code look like before you started storing results in memory?
> -----Original Message----- > From: Jay Sprenkle [mailto:[EMAIL PROTECTED] > Sent: Wednesday, April 20, 2005 10:06 AM > To: sqlite-users@sqlite.org > Subject: Re: [sqlite] Locking Methods > > I prepared the statement and executed it. > Preparing doesn't use callbacks and prevents sql injection attacks. > I used a C++ class to store the query results in an STL container. > > brief C/C++ pseudocode: > > string sql = "select * from blah"; > sqlite3_open(); > sqlite3_prepare( sql ); > bool Loop = true; > int retry = 0; > while ( loop && retry < 10 ) > switch ( sqlite3_step() ) > { > // if database busy wait for a short time > // to see if it becomes available > case SQLITE_BUSY: > case SQLITE_LOCKED: > retry++; > break; > case SQLITE_ROW: > // get results > retry = 0; > p = sqlite3_column_text(); > in_memory_list.push_back( p ); > break; > case SQLITE_DONE: > Loop = false; > break; > default: > string str = "Cannot execute sql: " + sql + ", Error: " + > sqlite3_errmsg(db); > throw str.c_str(); > break; > } > // clean up when finished > sqlite3_finalize(); > > //process your list here > > sqlite3_close( db ); > > > On 4/20/05, Thomas Briggs <[EMAIL PROTECTED]> wrote: > > > > What APIs are you guys using to retrieve results and execute the > > subsequent updates? Are you using prepare/step or > sqlite3_exec with a > > callback to retrieve the results? Would it be possible for > you to post > > more detailed pseudo-code? Conceptually I think we're all > on the same > > page; I think what we're unclear about is exactly how > you're trying to > > accomplish this. > > > > Thanks > > -Tom > > > > > -----Original Message----- > > > From: Ben Clewett [mailto:[EMAIL PROTECTED] > > > Sent: Wednesday, April 20, 2005 3:32 AM > > > To: sqlite-users@sqlite.org > > > Subject: Re: [sqlite] Locking Methods > > > > > > This is exactly my problem. My version is 3.1.6. The error is > > > SQLITE_LOCKED. > > > > > > Ben > > > > > > Jay Sprenkle wrote: > > > > I had the same trouble he did. Here's what I did that > doesn't work: > > > > > > > > select * from a into result; > > > > foreach row in result > > > > ' this fails: > > > > update b set col = a.value; > > > > next > > > > > > > > But based on what I read here it's supposed to do this. > > > > > > > > On 4/19/05, Gerry Blanchette <[EMAIL PROTECTED]> wrote: > > > > > > > >>Could you please elaborate your scenario? > > > >>I tried a test myself but am afraid I may not have > > > interpreted your test > > > >>case properly. > > > >> > > > >>I have 2 tables, fred and bob, each with 10000 rows. I > > > select a column > > > >>from fred and bind the value obtained from > sqlite3_column_int to an > > > >>update statement that operates on bob. I loop over fred via > > > >>sqlite3_step, where each iteration successfully updates the > > > row in bob. > > > >>Both tables exist in the same DB, accessed via the same > sqlite3 *. > > > >> > > > >>Have I misinterpreted your scenario somehow, as this > works for me? > > > >> > > > >>Thank you for helping clear this up for me. > > > >> > > > >>-- Gerry Blanchette > > > >> > > > >>-----Original Message----- > > > >>From: Ben Clewett [mailto:[EMAIL PROTECTED] > > > >>Sent: Monday, April 18, 2005 4:50 AM > > > >>To: sqlite-users@sqlite.org > > > >>Subject: [sqlite] Locking Methods > > > >> > > > >><snip> > > > >>I am experiencing problems with the locking. Because > SQLite uses > > > >>database locking this forces two major problems: > > > >> > > > >>- I can't read through a record set and use the data to > > > execute updates. > > > >> > > > >> For instance, some parsing exercise which cannot be > > > completed using a > > > >>single SQL command. I have to store all the data locally, > > > get to the > > > >>end of the query, then execute and update statements. > > > >> > > > >>Ben Clewett. > > > >></snip> > > > >> > > > > > > > > > > > > > > > > > > > -- > --- > You a Gamer? If you're near Kansas City: > Conquest 36 > https://events.reddawn.net > > The Castles of Dereth Calendar: a tour of the art and architecture of > Asheron's Call > http://www.lulu.com/content/77264 >
