🚀 go-pugleaf

Hi Mike

Hope you can get what you want from the following code snippet
from one of my test programs.


   int recNo;
   String pictureName, outPut, ext, picInd, colour, blank;

   blank = "";

   wDataModule->tPlants->Active = false;
   wDataModule->tPlants->Active = true;

   TField *field = (wDataModule->tPlants->FieldByName("JPGBMPImage"));
   TBlobField *blobField = dynamic_cast<TBlobField*>(field);
   TMemoryStream *stream = new TMemoryStream;

   recNo = 1;
   for (wDataModule->tPlants->First(); !wDataModule->tPlants->Eof;
        wDataModule->tPlants->Next())
   {
      wDataModule->tPlants->Edit();

      switch(recNo)
      {
         case 1  : pictureName = "C:\\MC\\Images\\Cus1.bmp";
                   colour = ExtractFileName(pictureName);
                   ext = ExtractFileExt(pictureName);
                   picInd = ext.SubString(2,3);
                   break;
         case 2  : pictureName = "C:\\MC\\Images\\Tulips.jpg";
                   colour = ExtractFileName(pictureName);
                   ext = ExtractFileExt(pictureName);
                   picInd = ext.SubString(2,3);
                   break;
         case 3  : pictureName = "C:\\MC\\Images\\Cus5.bmp";
                   colour = ExtractFileName(pictureName);
                   ext = ExtractFileExt(pictureName);
                   picInd = ext.SubString(2,3);
                   break;
         case 4  : pictureName = "C:\\MC\\ScanTest.bmp";
                   colour = ExtractFileName(pictureName);
                   ext = ExtractFileExt(pictureName);
                   picInd = ext.SubString(2,3);
                   break;
         case 5  : picInd = blank;
                   colour = blank;
                   break;
      }
      // No picture for Record 5
      if (recNo != 5)
      {
        stream->LoadFromFile(pictureName);
        stream->Position = 0;
        blobField->LoadFromStream(stream);
      }

      wDataModule->tPlants->FieldValues["Colour"] = colour;
      wDataModule->tPlants->FieldValues["JPGBMPInd"] = picInd;
      wDataModule->tPlants->Post();
      recNo++;
   }
   wDataModule->tPlants->Active = false;

   delete stream;

   wSecondForm->Memo1->Lines->Clear();
   wSecondForm->Memo1->Font->Color = clRed;
   outPut = "Images Loaded to Database record";
   wSecondForm->Memo1->Lines->Add(outPut);
   Sleep(2000);
   wSecondForm->Memo1->Font->Color = clBlack;


Michael Corby









"Mike K" <nospam@nospam.net> wrote in message 
news:47b9e51b$1@newsgroups.borland.com...
> I'm trying to retrieve a block of binary data (~5k bytes) from a SQL
> Server database table. The column name is 'data'.
>
> Using TADOQuery, I want to read the record, and write the data from the
> result set into memory. Also, I need to do the reverse (write the record). 
> This should not be rocket science.
>
> Here's what I have so far after a day and a half experimenting with
> snippets from old newsgroup posts:
>
>
> <snip>
> typedef struct{
> ...
> }CONFIG_DATA;
> CONFIG_DATA *cp;
> TADOQuery *iQuery;
> TBlobStream *bptr;
>
>
> iQuery->Active = false;
> iQuery->SQL->Clear();
> // just get one record:
> iQuery->SQL->Add("select data from config_data where ID = 3001");
> iQuery->Active = true;
>
> // got a runtime error before I put this line in:
> iQuery->Edit();
>
>
> bptr = 
> dynamic_cast<TBlobStream*>(iQuery->CreateBlobStream(iQuery->FieldByName("data"),bmRead));
>
> if(bptr) bptr = ReadBuffer(cp,bptr->Size);
> // home free if you get here!
>
> <end snip>
>
> Works fine until I get to CreateBlobStream(), which returns a null 
> pointer.  I've tried tons of methods to create the TBlobStream pointer,
> none of which work, many of which won't even compile (taken straight from 
> BCB5 help).
>
> This should not be difficult, but I'm having no luck.  I have been using 
> ADO database objects with BCB5 for years, just never had large binary 
> fields.
>
> Any kind soul who is willing to either give me the few lines of code I 
> need, or point me to a SPECIFIC WORKING example anywhere cyberspace, I 
> will happily add you to my Christmas card list (it's too late for a 
> valentine).
>
> TIA
>
> Mike
>
>
>
>
>
>