asked on

bytea get data from postgre

Greetings!
Am stuck on a bit tricky problem.
I am using ado components to access postgre database.
Same old problem everyone is experiencing, problems to store files into postgre database and retrieve them.
I have managed to store file into table in bytea field.
but main problem, i dont know how to retrieve files, since its not a really a blob.

i have managed to get down data 255 byte long, but not greater, cant figure out whats the problem.

any ideas?

procedure TForm1.Button1Click(Sender: TObject);
var
  ByteCount: integer;
  EncodedStr: WideString;
  MemStream: TMemoryStream;
  //// DecodeStream: TBase64DecodingStream;
  //Signal: array of byte;

begin
q.sql.Clear;
q.SQL.Add('select by from aaa');
q.Open;
q.last;

EncodedStr := q.FieldByName('by').asstring;
MemStream  := TMemoryStream.Create;
ByteCount  := length(q.FieldByName('by').AsString);

showmessage(inttostr(ByteCount)); // returns 255  only, why???

 MemStream.Write((EncodedStr[1]), ByteCount);
 MemStream.Seek(0, soFromBeginning);
 MemStream.SaveToFile('01.jpg');
end;

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Geert G

by is a reserverd word

>> order by

select [by] from aaa

KarlisB

ASKER

well, my mistake. but postgre is quite 'smart' and query works without problem.

my problem is how to get result into stream.

field[].asstring is wrong data type,
how can i get that bytea result into a stream???

Geert G

instead of deleting a question you could accept your own comment

this way you have it for your own reference
and for others too

ASKER CERTIFIED SOLUTION

KarlisB

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