{
If you develop a database related software, then a very popular task is to
save some files (documents/images/reports/etc) in some BLOB field of table
and use these saved data later.
In this tip I want to show how this task could be solved.
}
// To save a file to BLOB:
procedure TForm1.Button1Click(Sender: TObject);
var
blob: TBlobStream;
begin
blob := yourDataset.CreateBlobStream(yourDataset.FieldByName('YOUR_BLOB'), bmWrite);
try
blob.Seek(0, soFromBeginning);
fs := TFileStream.Create('c:\your_name.doc', fmOpenRead or
fmShareDenyWrite);
try
blob.CopyFrom(fs, fs.Size)
finally
fs.Free
end;
finally
blob.Free
end;
end;
// To load from BLOB:
procedure TForm1.Button1Click(Sender: TObject);
var
blob: TBlobStream;
begin
blob := yourDataset.CreateBlobStream(yourDataset.FieldByName('YOUR_BLOB'), bmRead);
try
blob.Seek(0, soFromBeginning);
with TFileStream.Create('c:\your_name.doc', fmCreate) do
try
CopyFrom(blob, blob.Size)
finally
Free
end;
finally
blob.Free
end;
end;
{
Using this code you can work with any database engine (BDE/ADO/DAO/ODBC/etc)
and any file format (document of MS Word, spreadsheet of MS Excel, bitmap or
jpeg pictures, wav-files etc)
}
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