Lazarus and Access-Database

[schand99]

Hi,

I have encountered a strange behaviour on Lazarus and MS Access database:
I open a SQL Query which selects a number of records. On the open records I have to check each record for the content of a field. I do this within a repeat ... until loop:

A error raises up when rSSQL.Next points to the last record into rSSQL, just befor rSSQL.EOF is true

Code: Pascal  [Select][+][-]

1. ...
2. rSSQL.open;
3. if not rSSQL.EOF do begin
4.    rSSQL.First;
5.    repeat
6.         ... do something
7.        rSSQL.Next;
8.    until rSSQL.EOF;
9. end;
10.  

If in the same code I first point to the last records and after that I point to the first record, there is no error
Is there anybody else having this problem? Or maybe someone who can explain this strange behavior?

Code: Pascal  [Select][+][-]

1. ...
2. rSSQL.open;
3. if not rSSQL.EOF do begin
4.    rSSQL.Last;           //  <- this one
5.    rSSQL.First;
6.    repeat
7.         ... do something
8.        rSSQL.Next;
9.    until rSSQL.EOF;
10. end;
11.  

[Zvoni]

I remember having similiar issues with DAO/ADO on VB6, that i had to move to the last record, and then back to the first, because the EOF and/or recordcount wasn't set properly or something like that.

[wp]

The attached demo does the same: it iterates through an Access-based dataset and counts the empty fields, and the error does not occur.

What is different to your case? I could imagine that the fact that the query is attached to a DBGrid in my demo could cause .Last already being called. So, please give more details, or better: upload a simple compilable demo (only pas, lfm, lpi, lpr and database files, all in a common zip, like I did).

[Zvoni]

Found something:
http://allenbrowne.com/ser-29.html
Look at Point 5. Sounds like your Problem