Dennis,
thanks for your and everyone elses help with this
problem. i actually did everything you said here and
the program executed without any errors.
i re-created the table to what you said as now so it
is blob now instead of text.
i get nothing. i have a printout statement to make
sure an imageID was created and it was successfully.
the array is indeed dynamic and has to be. to echo
this is what i have:
myString = "insert into Images(imageID, imageData)
values(?, ?);
status = sqlite3_prepare_v2(db, myString.c_str(), -1,
&statement, NULL);
void *blob = reinterpretcast<char *>(imageArray);
status = sqlite3_bind_blob(statement, 2, blob, 10 *
sizeof(unsigned short), SQLITE_STATIC);
statusu = sqlite3_finalize(statement);
return sqlite3_last_insert_row(db);
****************************
however when i do:
select * from Images;
i get no results returned to me. i just get returned
to the prompt. is there anything that i missed? thanks
again!!!
--- Dennis Cote <[EMAIL PROTECTED]> wrote:
> C S wrote:
> > hi all - i am trying once again to insert an
> image(an
> > array of shorts) into a blob.
> >
> > i created a table that is described as such:
> >
> > CREATE TABLE Images{
> > imageID integer primary key,
> > imageData text not null);
> >
> > #1 - is text ok here for a blob? maybe not - this
> may
> > be my entire problem.
> >
>
> I would recommend using a column type of BLOB for
> blob data just to
> avoid any confusion.
>
> CREATE TABLE Images (
> imageID integer primary key,
> imageData blob not null);
>
>
> > anyway instead of using data in an image i just
> made
> > an array of unsigned shorts and filled it. a size
> of
> > 10.
> >
> > so here is what i am doing in the code. imageArray
> > holds the unsigned shorts(there are 10 of them)
> >
> > char* blob = reinterpret_cast<char*>(imageArray);
> >
>
> Generally you should use a void* instead of a char*
> for blobs.
>
> void* blob = reinterpret_cast<void*>(imageArray);
>
> This pointer isn't needed if your imageArray is a
> true array of unsigned
> shorts rather than a pointer to some dynamically
> allocated memory.
>
> unsigned short imageArray[10] =
> {1,2,3,4,5,6,7,8,9,10};
>
>
> > string myString = "insert into Images(ImageID,
> > imageData) values(?, 'blob')";
>
> Note, this 'blob' is a string literal and has no
> relation at all to the
> blob variable you defined above. You need to use a ?
> for the second
> parameter as well so that you can bind a value to it
> later.
>
> string myString = "insert into Images(ImageID,
> imageData) values(?, ?)";
>
> >
> > //then i want to try to prepare the statement:
> >
> > int status = sqlite3_prepare_v2(db,
> myString.c_str(),
> > -1, &statement, NULL);
> > if( (status != SQLITE_OK) || (statement == NULL))
> > cout << "Error preparing SQL Statement" << endl;
> >
>
> There is no need to check statement here. SQLite
> will return an error
> code other than SQLITE_OK if it fails.
>
> >
> > //now i would like to bind the blob:
> >
> > status = sqlite3_bind_blob(statement, 1,
> imageArray,
> > 10 * sizeof(unsigned short), SQLITE_TRANSIENT);
> >
>
> The blob will be the second parameter to the
> statement. This parameter
> can be static as long as the image data will be
> stable until the
> statement is executed by sqlite3_step().
>
> If you want to use the blob pointer above you should
> do this:
>
> status = sqlite3_bind_blob(statement, 2, blob,
> 10 * sizeof(unsigned short), SQLITE_STATIC);
>
> If imageArray is a true array as shown above you can
> instead do this:
>
> status = sqlite3_bind_blob(statement, 2, imageArray,
> sizeof(imageArray), SQLITE_STATIC);
>
> You have not bound a value to the first parameter,
> the imageId column,
> so it will have a null value when the statement
> executes. This is OK
> since the column is declared as "integer primary
> key" and SQLite will
> assign a unique ID value.
>
> >
> > //execute statement for each row??
> > while( (status = sqlite3_step(statement)) ==
> > SQLITE_ROW);
> >
>
> There is no need for a while loop here. An insert
> statement can only
> step once, and sqlite3_step() will return
> SQLITE_DONE or some other
> error code.
>
> > //free the prepared statement
> > status = sqlite3_finalize(statement);
> > if(status != SQLITE_OK)
> > cout << "Error deleting prepared SQL statement"
> <<
> > endl;
> >
>
=====================================================
> >
> > i actually get the last status check output,
> saying
> > that there was an error deleting the statement.
> when i
> > looked that up it says there was a problem with
> the
> > prepare statement being successful or nothing
> happens
> > at all when clearly i did and clearly the status
> was
> > ok too since i didnt get an error message there.
> >
>
> I'm not sure why the finalize would fail, unless
> perhaps your prepare
> also failed, and you didn't have a valid statement
> pointer to pass to
> sqlite3_finalize().
>
> > can anyone help me out as to what might be going
> on
> > here? thanks so much in advance
> >
>
> HTH
> Dennis Cote
> _______________________________________________
> sqlite-users mailing list
> [email protected]
>
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
>
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