Storing jpegs in databases

I know that storing images in a database is oftern a bad idea.
However there can come requirements that force things on you.

For the database end I have used an IMAGE datatype in SQL Server.

The delphi approach is as follows:

You need to use GraphicEx to allow display in the normal controls.
All this requires is adding the GraphicEx unit to the end of your uses clause.

procedure LoadJPEGImageFromStream(const aImage: TImage;
  const stream: TStream);
var
  aJPEG : TJpegImage;
begin
    aJPEG := TJPEGImage.Create;
    try
      aJPEG.LoadFromStream(stream);
      aImage.Picture.Assign(aJPEG);
    finally
      aJPEG.Free;
    end;
end;

 

procedure LoadFromDB(Image : TImage; aField : TBlobField)
var
  aBLOBStream : TStream;
begin
  ado.Open;
  ado.First;

  aBLOBStream := adoFAX.CreateBlobStream(aField,bmRead);
  try
    LoadJPEGImageFromStream(Image, aBLOBStream );
  finally
    aBLOBStream.free;
  end;

end;
 

procedure SaveToDB(const filename : string)
var
  FS : TFileStream;
begin
  FS := TFileStream.Create(filename, fmOpenRead);
  try
    ado.open;
    ado.Insert;
    adoIMAGE.LoadFromStream(FS);
    ado.Post;
  finally
    FS.Free;
  end;
end;
 

Just to check that this is not a Delphi-only format I wrote the following test from C#:

            sqlDataAdapter1.Fill(dataSet11, “DB”);
            // How to get an image from a database in .NET                   
            pictureBox1.Image = new Bitmap( new MemoryStream( dataSet11.DB[0].IMAGE ) );
            pictureBox1.Height = pictureBox1.Image.Height;
            pictureBox1.Width = pictureBox1.Image.Width;
 

This loads the image previously stored by a Delphi app.

This ensures that the image format used is language neutral. 

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