Collection datatype FAIL

[sinys]

ODAC 9.3.10 XE2 Oracle 11g

Code: Select all

  OraSession1.ConnectString := 'Login Prompt=False;User ID=system;Password=manager';
  OraSession1.Connect;

  OraQuery1.SQL.Text := 'select cast(multiset(select level from dual connect by level<=10)as sys.ku$_objnumset) from dual';
  OraQuery1.Open;

  ShowMessage(IntToStr(OraQuery1.FieldCount));

Function ShowMessage return 0 (ZERO), why? I think this is error.

[AlexP]

Hello,

Such behaviour is related to the TDataSet.CreateFields method implementation in Delphi. The field type in your example is ftDataSet. In this case, a field is created if the DataSet ObjectView property is set to TRUE. So to resolve the problem, you need either set ObjectView to TRUE or create the Persistent Field in the design time.

[sinys]

But in this mode I see ftADT field like 1 field, but I want to see it like ObjectView = False. Make individual setting for it, please.

[AlexP]

We cannot change the ObjectView property value to True by default for ftDataSet fields, as this will cause changes in behaviour and errors in applications of our components users. If you have a Source Edition, we can show you where to add necessary changes.

[sinys]

I have Source Edition, but I don't want to change the source code of components in every new version. I don't propose to change the behavior of the ObjectView property, I ask you to add new property like FlatADTView (default false for not changing standard behavior of TOraQuery).
Example:

Code: Select all

create or replace type ComplexType as object(
x varchar2(100),
y varchar2(100)
);
/
---------
OraQuery1.SQL.Text := 'select ComplexType(CODE, name) A from TEST';
OraQuery1.ObjectView := True;
OraQuery1.FlatADTView := True; (new property)
OraQuery1.Open;

And I want to see:

Code: Select all

A.X | A.Y
1   |  2
3   |  4

like OraQuery1.ObjectView := False but this variant friendly for collections datatype.

[AlexP]

You can leave a suggestion to implement this feature at our uservoice page: http://devart.uservoice.com/forums/1046 ... components . Terms of the implementation will depend on the number of voices at Uservoice.

[sinys]

I added my request http://devart.uservoice.com/forums/1046 ... latadtview and some my collegs and clients voited for it already. But I think we are more speaking about it that doing it, because I asked about it long time ago http://forums.devart.com/viewtopic.php?f=5&t=28337 http://forums.devart.com/viewtopic.php?f=5&t=24825

[AlexP]

We implement new features depending on their complexity and relevance. These features are included to our ODAC development roadmap, however, their implementation is not planned for the nearest future.

[sinys]

Ok, please, show me what I must to change in source code for achive above behavior.

[AlexP]

To solve the problem, you should set the ObjectView property to True in the TOraDataSet.Create class constructor:

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constructor TOraDataSet.Create(Owner: TComponent);
begin
  inherited Create(Owner);

  CheckMode := cmNone;
  FSequenceMode := smPost;
  ObjectView := True;
{$IFNDEF FPC}
  NestedDataSetClass := TOraNestedTable;
{$ENDIF}
end;

[sinys]

Code: Select all

constructor TOraDataSet.Create(Owner: TComponent)
..
  ObjectView := True;

This mean that all TOraDataSet in my applications will have this behavior but I want this behavior only for 2 datasets in one of my application.

[AlexP]

Yes, this modification will affect all the fields of this type.

[sinys]

Could you please show me variant that I can use to 1-2 OraQuery only?

[AlexP]

Even if you set the ObjectView property in the constructor to True, this property will also be set to True in the DataSet, that own this field. Therefore you can just set the ObjectView property to True of the required DataSets.