revOpenDatabase Problem

Pete pete at mollysrevenge.com
Mon Dec 26 17:46:28 EST 2011


Thanks Andre and Mike.

Mike - thanks for the link.  You're right, that works just fine.  First 16
characters must be "SQLite format 3" plus a nul if it's an SQLite file.  LC
probably ought to be checking for that but that's OK.

On Mon, Dec 26, 2011 at 2:09 PM, Mike Bonner <bonnmike at gmail.com> wrote:

> Here, look here under 1.2 database header.
> http://www.sqlite.org/fileformat2.html   Looks like the first 16 bytes of
> the header are what you are looking for which are of course the first 16
> bytes of the file.  Should be quick and easy to grab those bytes and
> determine if the file is sqlite or not.
>
> On Mon, Dec 26, 2011 at 3:05 PM, Mike Bonner <bonnmike at gmail.com> wrote:
>
> > Hmm. don't have time to test it right this sec, but isn't an sqlite file
> > pretty much a regular old text file? If so, it might be possible to open
> > for read, read the first however much and check the file for validity.
> > (even if its binary, surely there is a way to determine if its really an
> > sqlite file) Would have to look up the sqlite file format but it seems
> like
> > it should be possible.
> >
> >
> > On Mon, Dec 26, 2011 at 3:00 PM, Pete <pete at mollysrevenge.com> wrote:
> >
> >> I think that's probably true.  I'm trying to figure out how to to tell
> if
> >> a
> >> real sqlite database was opened.  The first access to the db fails but
> the
> >> error is "Undefined SQLite error" which is not very specific!
> >>
> >> This is in an app where the user can select an sqlite db so I'm at the
> >> mercy of what they choose.  I did think about filtering the valid
> >> extensions for the ask file dialog but it's my understanding that an
> >> sqlite
> >> db can have any extension.  I also tried calling revDatabaseType  but
> that
> >> returns "SQLITE" even if it's not an sqlite database.
> >>
> >> Pete
> >>
> >> On Mon, Dec 26, 2011 at 1:42 PM, Mike Bonner <bonnmike at gmail.com>
> wrote:
> >>
> >> > My guess is that it doesn't check for a valid schema/format but that
> it
> >> is
> >> > only establishing a file handle which is successful. Then it should
> fail
> >> > with an error on actual attempt to use.
> >> >
> >> > On Mon, Dec 26, 2011 at 2:33 PM, Pete <pete at mollysrevenge.com> wrote:
> >> >
> >> > > Using revOpenDatabase to open an sqlite database using a file that
> is
> >> not
> >> > > an sqlite database return an integer as if the database was
> >> successfully
> >> > > opened.  Any subsequent db accesses fail of course but I wonder why
> >> > > revOpenDatabase doesn't return an error?
> >> > >
> >> > >
> >> > > --
> >> > > Pete
> >> > > Molly's Revenge <http://www.mollysrevenge.com>
> >> > > _______________________________________________
> >> > > use-livecode mailing list
> >> > > use-livecode at lists.runrev.com
> >> > > Please visit this url to subscribe, unsubscribe and manage your
> >> > > subscription preferences:
> >> > > http://lists.runrev.com/mailman/listinfo/use-livecode
> >> > >
> >> > _______________________________________________
> >> > use-livecode mailing list
> >> > use-livecode at lists.runrev.com
> >> > Please visit this url to subscribe, unsubscribe and manage your
> >> > subscription preferences:
> >> > http://lists.runrev.com/mailman/listinfo/use-livecode
> >> >
> >> >
> >>
> >>
> >> --
> >> Pete
> >> Molly's Revenge <http://www.mollysrevenge.com>
> >> _______________________________________________
> >> use-livecode mailing list
> >> use-livecode at lists.runrev.com
> >> Please visit this url to subscribe, unsubscribe and manage your
> >> subscription preferences:
> >> http://lists.runrev.com/mailman/listinfo/use-livecode
> >>
> >
> >
> _______________________________________________
> use-livecode mailing list
> use-livecode at lists.runrev.com
> Please visit this url to subscribe, unsubscribe and manage your
> subscription preferences:
> http://lists.runrev.com/mailman/listinfo/use-livecode
>
>


-- 
Pete
Molly's Revenge <http://www.mollysrevenge.com>



More information about the Use-livecode mailing list