> -----Original Message----- > From: D. Richard Hipp [mailto:[EMAIL PROTECTED] > Sent: Sunday, July 10, 2005 6:01 PM > To: sqlite-users@sqlite.org > Subject: RE: [sqlite] Binding a column name? > > On Sun, 2005-07-10 at 15:34 -0700, Tim McDaniel wrote: > > > > > > If another thread or process VACUUMs the database or > creates a new > > > table or makes any other structure changes to the > database file, all > > > of your prepared statements will be invalided and you > will have to > > > rerun sqlite3_prepare(). > > > Since you generally have no control over when another > process might > > > VACUUM the database, you should always be prepared to rerun > > > sqlite3_prepare() if necessary. This is true even if you > are only > > > running your SQL statement once and then finalizing it because > > > another process might VACUUM and invalidate your statement in the > > > very brief window of time between your calls to sqlite3_prepare() > > > and sqlite3_step(). > > > > > > Your best bet it to use a wrapper class of some sort that > automates > > > the task of rerunning sqlite3_prepare() when necessary. > > > > > > > Does sqlite store the SQL text passed into sqlite3_prepare? > > If not, then I assume this means that any time we use > sqlite3_prepare, > > we should cache the SQL text "in the wrapper" in case we need to > > re-prepare it. > > Yes. The wrapper needs to keep the SQL text because SQLite does not. > > > Along the same line, I suppose we have to cache all the bound > > parameters, since they will have to re-bound as well. > > You can do that. Or you can keep the old prepared statement > around until after the new one is ready, then use the > sqlite3_transfer_bindings() API to transfer all your bindings > from the old to the new, then finalize the old. > > > > > Is it possible to get the SQLITE_SCHEMA error after the first > > sqlite3_step call, while iterating throw the rows? > > > > No. SQLITE_SCHEMA will always appear immediately or not at all. > --
Is there any advantage to using sqlite3_expired() vs just sqlite3_step(), since you have to check for SQLITE_SCHEMA anyway?
