Wow, Peter, didn't expect that anyone would go to the trouble of writing a
program on the spot....
Just curious, but from those few things that I have seen, it appears that
you can only put a Blob into the DB if it is already on disc, right? All
three examples I have seen passed the filename to the database, and one of
them was working within a server context, so I wasn't sure how the local
filename would be of any use to a machine that is in another part of the
room (or anywhere else...).
Just so you understand what it is I am trying to do, I am working in a
Multimedia programming environment (Pure Data), and I would like to be able
to read and write some chunks of audio or video as needed. While Pure Data
is a realtime environment, I am not expecting this to be responsive to work
in realtime.
Thanks again, I will study this to see if it tells me anything more...
Mike
On Wed, Feb 27, 2008 at 8:02 PM, Peter A. Friend <[EMAIL PROTECTED]>
wrote:
>
> On Feb 27, 2008, at 4:48 PM, Mike McGonagle wrote:
>
> > Hello all,
> > I was hoping that someone might share some tips on working with
> > Blobs? I
> > would like to be able to store some images and sound files in a
> > database,
> > but never having dealt with them, I am kind of at a loss for some
> > examples.
> > I have looked on the web, and there are few examples that were of use.
>
> Well, I wrote a quick and dirty program for stuffing image files into
> a database. You just provide a directory and it stats() each file,
> allocates enough space for the image data, then loads it from disk.
> Sql statement is something like:
>
> char* sql = "insert into i (name, data) values (?, ?);";
>
> Of course if your images are huge this method coud be problematic. I
> believe SQLite supports an incremental way to do this but I haven't
> looked at those calls yet.
>
> while ( (dentry = readdir(dir)) != '\0') {
> if (dentry->d_name[0] == '.')
> continue;
>
> if (fd != -1) {
> close(fd);
> fd = -1;
> }
>
> if (data != '\0') {
> free(data);
> data = '\0';
> }
>
> snprintf(fname, sizeof(fname), "%s/%s", newdir, dentry->d_name);
> stat(fname, &sb);
>
> if ( (data = malloc(sb.st_size)) == '\0') {
> fprintf(stderr, "malloc() failed\n");
> sqlite3_finalize(stmt);
> sqlite3_close(db);
> exit(1);
> }
>
> if ( (fd = open(fname, O_RDONLY, 0000)) == -1) {
> fprintf(stderr, "open() failed\n");
> sqlite3_finalize(stmt);
> sqlite3_close(db);
> exit(1);
> }
>
> if ( (retval = read(fd, data, sb.st_size)) == -1) {
> fprintf(stderr, "read() failed\n");
> sqlite3_finalize(stmt);
> sqlite3_close(db);
> exit(1);
> }
>
> if (retval != sb.st_size) {
> fprintf(stderr, "read() failed\n");
> sqlite3_finalize(stmt);
> sqlite3_close(db);
> exit(1);
> }
>
> rc = sqlite3_bind_text(stmt, 1, dentry->d_name, dentry->d_namlen,
> SQLITE_STATIC);
>
> if (rc != SQLITE_OK) {
> fprintf(stderr, "sqlite3_bind_text() %s\n", sqlite3_errmsg
> (db));
> sqlite3_finalize(stmt);
> sqlite3_close(db);
> exit(1);
> }
>
> rc = sqlite3_bind_blob(stmt, 2, data, sb.st_size, SQLITE_STATIC);
>
> if (rc != SQLITE_OK) {
> fprintf(stderr, "sqlite3_bind_blob() %s\n", sqlite3_errmsg
> (db));
> sqlite3_finalize(stmt);
> sqlite3_close(db);
> exit(1);
> }
>
> rc = sqlite3_step(stmt);
>
> if (rc != SQLITE_DONE) {
> fprintf(stderr, "sqlite3_step() %s\n", sqlite3_errmsg(db));
> sqlite3_finalize(stmt);
> sqlite3_close(db);
> exit(1);
> }
>
> sqlite3_reset(stmt);
> }
>
> _______________________________________________
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> sqlite-users@sqlite.org
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>
--
Peace may sound simple—one beautiful word— but it requires everything we
have, every quality, every strength, every dream, every high ideal.
—Yehudi Menuhin (1916–1999), musician
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