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TMS Aurelius Documentation

In TAureliusDataset, each field represents a property in an object. So, for example, if you have a class declared like this:

 

  TCustomer = class

  // <snip>

  public

    property Id: Integer read FId write FId;

    property Name: string read FName write FName;

    property Birthday: Nullable<TDate> read FBirthday write FBirthday;

  end;

 

when providing an object of class TCustomer to the dataset, you will be able to read or write its properties this way:

 

CustomerName := AureliusDataset1.FieldByName('Name').AsString;

if AureliusDataset1.FieldByName('Birthday').IsNull then

  AureliusDataset1.FieldByName('Birthday').AsDateTime := EncodeDate(198011);

 

As with any TDataset descendant, TAureliusDataset will automatically create default fields, or you can optionally create TField components manually in the dataset, either at runtime or design-time. Creating persistent fields might be useful when you need to access a field that is not automatically present in the default fields, like a sub-property field or when working with inheritance.

 

The following topics explain fields usage in more details:

 

Default Fields and Base Class

Self Field

Sub-Property Fields

Entity Fields (Associations)

Dataset Fields (Many-Valued Associations)

Heterogeneous Lists (Inheritance)