Are you able to load and save the bitmap to a file?

On Fri, Aug 29, 2008 at 2:13 PM, Jared Miller <[EMAIL PROTECTED]> wrote:
> Hello,
> I am having trouble figuring out how to successfully write an image to the 
> SQLite database as a Blob, using C++.
> I have an HBITMAP that I would like to be able to store to and retrieve from 
> the DB. If I understand what I have read correctly, I am supposed to write 
> out the actual byte data to the DB. Here is what I have done so far.
> I pass in pbyBitmap as the bmBytes parameter to this function:
> ImportPageImage(CPage* pPage, BYTE* bmBytes, DWORD bmSize), which calls the 
> code below. . .
> //prepare query
> static const WCHAR tblInsertBlob[] = _T("Insert into [tblBlob] ([Data]) 
> values (?)");
> SQL_HANDLE blobHandle = m_pSqliteDB->PrepareQuery16(tblInsertBlob); //calls 
> sqlite3_prepare16()
> //bind blob
> m_pSqliteDB->BindBlob(blobHandle, 1, (void *)bmBytes, bmSize); //calls 
> sqlite3_bind_blob (bmBytes is the pData param)
> Then I call StepQuery to execute it, and then I close the query. 
> sqlite3_bind_blob() returns SQLITE_OK when I run it, so it does not seem to 
> be encountering an error there.
> Something apparently gets written to the database, but it does not seem to be 
> correct. When I try to retrieve and display my image, it is all black (which 
> is how bitmaps look when there is no data).
> I think that the problem is coming from writing the BLOB to the database, but 
> I am not entirely sure. Just in case it is getting written properly and I am 
> not reading it from the database correctly, I will show you how I pulled it 
> from the DB.
> //prepare blob
> sqlite3_blob* pBlob = NULL;
> sqlite3_blob_open(m_sqliteDB, "main", "tblBlob", "Data", iBlobID, FALSE, 
> &pBlob);
> BLOB_HANDLE hBlob = pBlob;
> int size = sqlite3_blob_bytes(hBlob); //works correctly, returns 998058
> BYTE* pBuffer = g_MemMgr.AllocDataBuffer(size);
> sqlite3_blob_read(hBlob, pBuffer, size, 0); //returns SQLITE_OK
> sqlite3_blob_close(hBlob);
> I then try to make a bitmap out of the bytes in pBuffer, but when I do, it 
> turns out all black (as I mentioned earlier).
> Do I have the concept correct? And if so, what part of my current code should 
> I change to be able to use my DB to store image data?
> Thanks a lot.
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