Devart Forums

Code: Select all

program Project1;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils,
  Data.DB,
  VirtualTable;

var
  VT: TVirtualTable;

  procedure fill(id: integer; const text: string);
  begin
    VT.Append;
    VT.Fields[0].AsInteger := id;
    VT.Fields[1].AsString := text;
    VT.Post;
  end;

  procedure show;
  var
    i: integer;
  begin
    VT.First;
    while not VT.Eof do begin
      for i := 0 to VT.FieldCount - 1 do
        Write(VT.Fields[i].AsString + #9);
      Write(#13#10);
      VT.Next;
    end;
    WriteLn('----------------------')
  end;

  procedure SetIndex(const IndexFieldNames: string);
  begin
    Vt.IndexFieldNames := IndexFieldNames;
  end;

begin
  VT := TVirtualTable.Create(nil);
  try
    VT.AddField('ID', ftInteger);
    VT.AddField('TEXT', ftString, 10);
    VT.Open;
    fill(1, 'b');
    fill(2, 'c');
    fill(1, 'a');
    fill(2, 'a');
    fill(1, 'c');
    fill(2, 'b');
    show;
    SetIndex('ID');
    show;
    SetIndex('');
    SetIndex('TEXT');
    show;
    SetIndex('');
    SetIndex('ID;TEXT');
    show;
    SetIndex('');
    SetIndex('TEXT;ID');
    show;
    VT.Close;
  finally
    VT.Free;
    readln;
  end;
end.

Code: Select all

procedure Search_Value(ID:longint; Tekst, Tekst2:string; var X_rec:TX_rec);
begin
  fillChar(X_rec, sizeOf(X_rec), 0);

  if ID<>0 then  begin
    if  VT_Indexed_by_ID.Locate('ID', ID) then begin
       X_rec.ID   :=VT_Indexed_by_ID.FieldByName('ID').AsInteger;
       X_rec.Text:=VT_Indexed_by_ID.FieldByName('Text').AsString;
       X_rec.Text2:=VT_Indexed_by_ID.FieldByName('Text2').AsString;
    end;
  end else begin
    if (Tekst<>'') and (VT_Indexed_by_Text_Text2.Locate('Tekst;Tekst2', Text+Text2)) 
    then begin
       X_rec.ID   :=VT_Indexed_by_Text_Text2.FieldByName('ID').AsInteger;
       X_rec.Text:=VT_Indexed_by_Text_Text2.FieldByName('Text').AsString;
       X_rec.Text2:=VT_Indexed_by_Text_Text2.FieldByName('Text2').AsString;
    end;
  end;
end;