Hi Mike,
The data in this example happens to come from file, but that isn't
relevant. The line:
rc = sqlite3_bind_blob(stmt, 2, data, sb.st_size, SQLITE_STATIC);
is binding a chunk of data on the heap to the blob column and
inserting that into the database. Where this chunk of data comes from
isn't relevant. HTH.
Thursday, February 28, 2008, 2:35:27 PM, you wrote:
MM> Wow, Peter, didn't expect that anyone would go to the trouble of writing a
MM> program on the spot....
MM> Just curious, but from those few things that I have seen, it appears that
MM> you can only put a Blob into the DB if it is already on disc, right? All
MM> three examples I have seen passed the filename to the database, and one of
MM> them was working within a server context, so I wasn't sure how the local
MM> filename would be of any use to a machine that is in another part of the
MM> room (or anywhere else...).
MM> Just so you understand what it is I am trying to do, I am working in a
MM> Multimedia programming environment (Pure Data), and I would like to be able
MM> to read and write some chunks of audio or video as needed. While Pure Data
MM> is a realtime environment, I am not expecting this to be responsive to work
MM> in realtime.
MM> Thanks again, I will study this to see if it tells me anything more...
MM> Mike
MM> On Wed, Feb 27, 2008 at 8:02 PM, Peter A. Friend <[EMAIL PROTECTED]>
MM> 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);
>> }
>>
>> _______________________________________________
>> sqlite-users mailing list
>> sqlite-users@sqlite.org
>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
>>
--
Best regards,
Neville Franks, http://www.surfulater.com http://blog.surfulater.com
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