Hi, I have two TSQLite3Dataset components:

DatasetSales with the fields: Code, Item, Amount, Price, Vendor DatasetItems with the fields: Code, Description

I have a TDBGrid component that shows the data of DatasetSales.

I want to make a lookup field associated to the Item DatasetSales field to show the Code and Description DatasetItems fields.

I do it:

Code:

procedure TForm1.FormCreate(Sender: TObject);
begin
  with DatasetSales do
  begin
  Open;
  DatasetItems.Open;
  FieldByName('Item').FieldKind := fkLookup;
  FieldByName('Item').LookupDataSet := DatasetItems;
  FieldByName('Item').LookupKeyFields := 'Code; Description';
  FieldByName('Item').LookupResultField := 'Code';
  end;
end;

but nothing happen.

Why?

Thanks and Merry Christmas.
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It's not implemented in TSqlite3Dataset. In fact i don't know in which layer (TDataset / TDataset descendant / TDbGrid) should be implemented.

It's up to TDataset descendants implement this?

Does some descendant already implemented ?

Luiz

1) You forgot to set KeyFields
(or, rather, FieldName -- it should be different form KeyFields or DBGrid might be confused)
2) You probably mixed up LookupKeyFields with LookupResultField
3) If you want the lookup field to be editable, you will need to use Lazarus version later then http://bugs.freepascal.org/view.php?id=12347 and to set LookupCache := true
4) Even after this, there is some problems in SQLdb which I did not yet found time
to diagnose and fix properly. They cause AVs while scrolling DBGrid.

It seems to be implemented in SQLdb (TBufDataset). So, in addition to the above, original poster should indeed drop sqlitedataset. Perhaps TSQLite3Connection can be ised instead?

4) Even after this, there is some problems in SQLdb which I did not yet found time to diagnose and fix properly. They cause AVs while scrolling DBGrid.at are very hard t find

Dont spend too much time in this SQLite3DataSet has a lot of Bugs. ill tryed to fix all for month before i used zeos

4) Even after this, there is some problems in SQLdb which I did not yet found time to diagnose and fix properly. They cause AVs while scrolling DBGrid.at are very hard t find

Dont spend too much time in this SQLite3DataSet has a lot of Bugs. ill tryed to fix all for month before i used zeos

Hi again, my TSQLite3Dataset components:

DatasetSales with the fields: Code, Item, Amount, Price, Vendor DatasetItems with the fields: Code, Description

I do not want that the lookup field to be editable.

My new code:

procedure TForm1.FormCreate(Sender: TObject);
var
  TempField: TStringField;
begin
  DatasetSales.Active := true;
  TempField := TStringField.Create(DatasetSales);
  with TempField do
    begin
      FieldName := 'New field';
      Lookup := True;
      FieldKind := fkLookup;
      KeyFields := 'Item';
      LookupDataSet := DatasetItems;
      LookupKeyFields := 'Code';
      LookupResultField := 'Description';
      DatasetSales := Self.DatasetSales;
    end;
end;

but nothing happen. Why?

2008/12/25 Alexander Klenin :

Can you point what bugs? Maybe you can report them.

All reported bugs, that are inherently to Sqlite3Dataset and doable of reproduction where fixed.

Luiz

1) There's a bug in your code:

DatasetSales := Self.DatasetSales;
should be
Dataset := DatasetSales;

and Active should be set after the field setup.

Another caution is to have DatasetItems opened before DatasetSales

2) It's not implemented in TSqlite3Dataset
I looked at the implementation and got how it works, so i can implement in Sqlite3Dataset soon.

Luiz

User wrote

Hi again, my TSQLite3Dataset components: My new code:

[skip]

but nothing happen. Why?

Because, as I already pointed out:

Alexander Klenin wrote

It seems to be implemented in SQLdb (TBufDataset). So, in addition to the above, original poster should indeed drop sqlitedataset. Perhaps TSQLite3Connection can be ised instead?

Op donderdag 25-12-2008 om 14:06 uur [tijdzone +0100], schreef :

So where are all those bug-reports? Without those they will never get solved.

Becides that, ZEOS is made for another purpose. TSQLite3DataSet is made for what SQlite is made for: a lite and quick database-access layer.

ZEOS is made for 'heavier' usage, and often overkill when it comes to sqlite. And considerably slower.

Both have their own uses.

Joost.

http://bugs.freepascal.org/view.php?id=11423 at example

some of the problems i had was very hard to not reproduceable and the first bugreports i made are ignored so i use zeos and have no problem. when i become bad answers or the developer ignores me when i make bugreports and patches i dont use the component anymore.

when somebody is realy intrested in my patches for it please send an mail to me then i will send back my patches when ill find them i have resolved all problems i can so taht sqlite3dataset had react like an normal tdataset descendant (master detail & co) but after that some very hard errors with crashes & co remains and it was to bad for me, so i searched another solution wich was zeos.

best regards
Christian

Op zaterdag 27-12-2008 om 14:06 uur [tijdzone +0100], schreef :

In the bug report you said you would send an example. But I still don't see it. Can you send it, so we can actually look at your bug?

Joost.

havend time for now. Maybe later its good described should be manageable to have in 5 min an example. But i must go now must be at the ostsee in 3h ;)

best reagrds
Christian

[..]

2) It's not implemented in TSqlite3Dataset I looked at the implementation and got how it works, so i can implement in Sqlite3Dataset soon.

I implemented support to Calc/Lookup fields in fpc trunk. It would be good if someone could test because i don't use this feature much.

Luiz