Most applications do not explicitly create instances of TIntegerField. Instead, the field components are created automatically, as persistent field components defined in the Fields editor at design time or as dynamic field components created automatically by the dataset. 

Create sets the DataType property to ftInteger, MinValue to -2147483648, and MaxValue to 2147483647. The AOwner parameter specifies the component, typically a dataset, that becomes the new field's Owner. The Owner is responsible for freeing the component. 

In the rare cases when you must create a persistent field component at runtime, call Create to create and initialize an instance of TIntegerField. After instantiating a TIntegerField, associate it with a specific field by setting its FieldName property to the name of the field. Give the TIntegerField a unique identifier in the Name property. Establish where the field appears in the collection of fields by providing an ordinal number in the Index property. Associate the TIntegerField with a dataset component by setting its DataSet property. 

The example below creates a TIntegerField object for a field named Quantity accessed through a TSQLDataSet named SQLDataSet1.

var
  T: TIntegerField;
begin
  SQLDataSet1.Close;
  T := TIntegerField.Create(SQLDataSet1);
  T.FieldName := 'Quantity';
  T.Name := SQLDataSet1.Name + T.FieldName;
  T.Index := SQLDataSet1.FieldCount;
  T.DataSet := SQLDataSet1;
  SQLDataSet1.FieldDefs.UpDate;
  SQLDataSet1.Open;
end;

SQLDataSet1->Close();
TIntegerField *T = new TIntegerField(SQLDataSet1);
T->FieldName = "Quantity";
T->Name = SQLDataSet1->Name + T->FieldName;
T->Index = SQLDataSet1->FieldCount;
T->DataSet = SQLDataSet1;
SQLDataSet1->FieldDefs->UpDate();
SQLDataSet1->Open();

Destroy 

DataType 

MinValue 

MaxValue 

Owner