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Saving other file format in LONGBLOB (mySQL)

Posted on 2006-06-26
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Last Modified: 2010-04-05
Hi,

 I have a field named "Media" with LongBlob datatype. I store image, audio, video or any file format in this "Media" field. my question now is how to convert the data stored inside "Media" back to its original format and save it in my harddrive?

I already have the code in saving and loading an image(jpg or bmp) file in my "Media" field. My problem also is in how to save and load other file format aside from images inside my LongBlob field.


------------------------------------------------------------------
I  used this to save image in my Media (blob fieldtype)
   ms := TMemoryStream.Create;
   Image1.Picture.Graphic.SaveToStream(ms);
   ms.Position := 0;
   TBlobField(oTable.FieldByName('MEDIA')).LoadFromStream(ms);
-------------------------------------------------------
And used this to load my image in the TIMAGE
Procedure TfDigitalMed.InitializeForm;
var
  ms : TStream;
  gr : TBitmap;
begin
  ms := oTable.CreateBlobStream(oTable.FieldByName('MEDIA'), bmRead);
  gr := TBitmap.Create;
  gr.LoadFromStream(ms);
  Image1.Picture.Bitmap.Assign(gr);
  gr.Free;
  ms.Free;
end;
---------------------------------------------------------------
0
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Question by:ryan_sabarre
  • 4
  • 3
8 Comments
 

Author Comment

by:ryan_sabarre
ID: 16981745
THANKS AGAIN
0
 
LVL 14

Expert Comment

by:Pierre Cornelius
ID: 16981751
...
var fs: TFileStream;
begin
  fs := TFileStream.Create(SomeFileName, fmOpenRead);
  try
   fs.Position := 0;
   TBlobField(oTable.FieldByName('MEDIA')).LoadFromStream(fs);
  finally
    fs.Free;
  end;
...
0
 

Author Comment

by:ryan_sabarre
ID: 16983447
can you please complete the code. :-) is there any savetofile method capability?
0
 
LVL 4

Expert Comment

by:JDSkinner
ID: 16983648
Take a look at the following link
Called 'save a file to a TBlobStream and read it back'
http://www.swissdelphicenter.ch/en/showcode.php?id=1271
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LVL 14

Accepted Solution

by:
Pierre Cornelius earned 50 total points
ID: 16984166
for saving you could do this:

...
var fs: TFileStream;
begin
  fs:= TFileStream.Create(SomeFilename, fmCreate);
  try
    TBlobField(oTable.FieldByName('MEDIA')).SaveToStream(fs);    
  finally
    fs.Free;
  end;
0
 

Author Comment

by:ryan_sabarre
ID: 16984363
Hi last one, how can i clear value inside "Media" field?

 oTable.FieldByName('MEDIA')).asvariant:=nil; ???

0
 
LVL 14

Expert Comment

by:Pierre Cornelius
ID: 16985928
No, do this:

  TBlobField(oTable.FieldByName('MEDIA')).Clear;
0
 

Author Comment

by:ryan_sabarre
ID: 16989295
THANKS A LOT PierreC!
0

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