Manually create a IDADataSet containing a dynamic set of field an values (Delphi)

Data Abstract
1

Hi,

We want to return a IDADataSet that contains dynamic fields and values.
Normally we return a DataSet like this:

dataSet := fConnection.NewDataset(selectSql, ‘FutureValues’);
dataSet.Open;
result := Binary.Create;
DataStreamer.WriteDataset(Result, dataSet, [woRows, woSchema], -1)

Where selectSql contains a dynamically build sql statement.
This works fine.

In some other cases we want to return a DataSet that will contain a single row and data that cannot be expressed as a sql statement.
Basically we would like to do something like
DataSet.Fields.Add…
DataSet.Fields[x].Value :=
DataStreamer.WriteDataset(Result, dataSet, [woRows, woSchema], -1)

Is this possible???.

I tried to do this, but got an error about a RemoteDataAdapter not being assigned (I guess because this is suppoes to be used client side)

memTable := TDACDSDataTable.Create(Nil);
memTable.LogicalName := ‘FutureValues’;
singleField := memTable.FIelds.Add;
singleField.DataType := datString;
singleField.Size := 30;
singleField.SQLOrigin := ‘naam’;
singleField.DisplayName := ‘Naam’;

memTable.Open;
memTable.Insert;
memTable.AddRecord([‘naam’], [‘Test’]);
memTable.Post;
memTable.First;
DataStreamer.WriteDataset(Result, memTable, [woRows, woSchema], -1)

regards
Paul Sjoerdsma

2

Hello,
Please do the following:

  1. Use TDAMemDataTable instead of TDACDSDataTable.
  2. Set TDAMemDataTable.RemoteFetchEnabled to False
3

Aah, ok I forgot to mention that we are still using an old version of RemObjects (actually still using Delphi 2007).
We are within 2 months are moving to Delphi XE and latest RemObjects, but for now we do not have TDAMemDataTable…

4

Hello,

  1. Set TDACDSDataTable.RemoteFetchEnabled to False
  2. AddRecord contains Insert and Post. Don’t use them together.
    In your case:
 
................................
memTable.Open;

memTable.Insert;
memTable.FieldByName('naam').AsString := 'Test';
memTable.Post;
//or
memTable.AddRecord(['naam'], ['Test']);

memTable.First;
5

Hi,
This is the code I have

memTable := TDACDSDataTable.Create(Nil);
memTable.RemoteFetchEnabled := False;
memTable.LogicalName := ‘FutureValues’;

singleField := memTable.Fields.Add;
singleField.DataType := datString;
singleField.Size := 30;
singleField.SQLOrigin := ‘naam’;
singleField.DisplayName := ‘Naam’;

memTable.Open;
memTable.FieldByName(‘naam’).asString := ‘Test’;

memTable.Post;

memTable.First;

When this code is executed I get an error : “Cannot find field Item1” in
procedure TDACustomFieldCollection.Bind(aDataset: TDataset);
This happens on the memtable.Open call

By the way we are using version 4.0.19.565

regards
Paul

6

Ok, it seems I forgot to set a property singleField.Name
Seems to work better now