Solved

Problem with BLOB field

Posted on 1997-06-23
3
323 Views
Last Modified: 2010-04-04
I'am try to save some binary data to a blob field, via a
blob stream. The problem is I get a "BLOB not opened error".
Code fragment

  }
   Table1Data is a persistent field of TBlobField Type
  {
 
   DStream := TBlobStream.Create(Form1.Table1Data,
   bmReadWrite);
   While Not EOF(DataFile) DO
     Begin
      BlockRead(DataFile,HeaderRecord,SizeOf(HeaderRecord),
                                                 NumRead);
      EndOfHeader := FilePos(DataFile);
      For i := 0 To HeaderRecord.RecCount -1 DO
       Begin
         BlockRead(DataFile,DataRecord,SizeOf(DataRecord),
                                                 NumRead);
         FieldPos := DStream.Write(DataRecord,
                             SizeOf(DataRecord));
       End;

I have no problems with the other fields in the table
0
Comment
Question by:mikedodsworth
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 1

Accepted Solution

by:
Gabor earned 150 total points
ID: 1337632
The easiest way is to save the data from your datafile to the blob as a whole:var  fs: TFileStream;begin  fs:=TFileStream.Create(DataFileName,fmRead);  try    Form1.Table1Data.LoadFromStream(fs);  finally    fs.Free;  end;end;If you have to use your own code, I think you have to set table to edit state with the Edit method.
0
 
LVL 1

Expert Comment

by:Gabor
ID: 1337633
Sorry mikedodsworth, but my CR-s disappeard. I don't know why.
0
 

Author Comment

by:mikedodsworth
ID: 1337634
Gabor, I have tried putting the edit mode but it still fails.
The problem with saving the data file as whole is that
the file contains many seperate records with header info.So I
am still open to offers on the orignal code.
Thanks Mike.
 
0

Featured Post

On Demand Webinar - Networking for the Cloud Era

This webinar discusses:
-Common barriers companies experience when moving to the cloud
-How SD-WAN changes the way we look at networks
-Best practices customers should employ moving forward with cloud migration
-What happens behind the scenes of SteelConnect’s one-click button

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Dev express lookupcombo 3 45
How to make Sign in, using Clientdataset? 1 33
Delphi android app hide keyboard 3 43
Broadcast a message using ICS 2 23
In this tutorial I will show you how to use the Windows Speech API in Delphi. I will only cover basic functions such as text to speech and controlling the speed of the speech. SAPI Installation First you need to install the SAPI type library, th…
Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
How to Install VMware Tools in Red Hat Enterprise Linux 6.4 (RHEL 6.4) Step-by-Step Tutorial

749 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question