TIndexDefs.AddIndexDef Method

Creates a new index definition object and adds it to the Items property.

Pascal

function AddIndexDef: TIndexDef;

C++

__fastcall TIndexDef AddIndexDef();

Description

Call AddIndexDef to add index definitions when creating a database table. AddIndexDef returns the new TIndexDef object that was added to the IndexDefs collection of index definitions. After calling AddIndexDef, set the properties of the newly added TIndexDef object to specify the name, type, and options of index that will be created.

Note: AddIndexDef is only valid in the context of creating index definitions for a table to be created with a subsequent call to the CreateTable

or CreateDataSet method. It cannot be used to add indexes to an already-existing table.

C++ Examples:

Copy Code

/*
The following code creates and activates a client dataset in
the form’s OnCreate event handler.
*/ 
void __fastcall TForm1::FormCreate(TObject *Sender)
{
  TFieldDefs *pDefs = CDS2->FieldDefs;
  TFieldDef *pDef = pDefs->AddFieldDef();
  pDef->DataType = ftInteger;
  pDef->Name = "Field1";

  pDef = pDefs->AddFieldDef();
  pDef->DataType = ftString;
  pDef->Size = 10;
  pDef->Name = "Field2";

  TIndexDef *pIDef = CDS2->IndexDefs->AddIndexDef();
  pIDef->Fields = "Field1";
  pIDef->Name = "IntIndex";

  CDS2->CreateDataSet();
}

Delphi Examples:

Copy Code

{
The following code creates and activates a client dataset in
the form’s OnCreate event handler.
} 
procedure TForm1.FormCreate(Sender: TObject);
begin
  with CDS2 do
  begin
    with FieldDefs.AddFieldDef do
    begin
      DataType := ftInteger;
      Name := 'Field1';
    end;
    with FieldDefs.AddFieldDef do
    begin
      DataType := ftString;
      Size := 10;
      Name := 'Field2';
    end;
    with IndexDefs.AddIndexDef do
    begin
      Fields := 'Field1';
      Name := 'IntIndex';
    end;
    CreateDataSet;
  end;
end;