Title: to save file in BLOB and read from BLOB
Question: How to save some file in BLOB-field and use it later
Answer:
If you develop a database related software, then 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:
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;
To load from BLOB:
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;
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)
With best regards, Mike Shkolnik
E-Mail: mshkolnik@scalabium.com
WEB: http://www.scalabium.com