unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, Grids, DBGrids, DBTables;

type
  TForm1 = class(TForm)
    DBGrid1: TDBGrid;
    DataSource1: TDataSource;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    Query1: TQuery;
  end;

var
  Form1: TForm1;
  Field1: TFloatField;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  Query1 := TQuery.Create(Self);
  Field1 := TFloatField.Create(nil);
  Field1.FieldName := 'Cislo';
//  Field1.Size := 5;
  Field1.DisplayWidth := 5;
  Field1.Precision := 2;
  Query1.Fields.Add(Field1);
  Query1.Active := True;
  DataSource1.DataSet := Query1;

  try
    Query1.Append;
    Query1.Fields[0].AsFloat := 10;
    Query1.Post;
  finally
  end;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  Query1.Free;
end;

end.

Čo robím zle? Ak povolím riadok Field1.Size, tak dostanem chybu, že je to chybná dĺžka, ak to nepovolím, tak pri Active := True dostanem "No SQL statement available". Keďže je tabuľka vytváraná v pamäti, tak jej fyzické meno neexistuje. Zrejme je chyba niekde v tom. Tiež by ma zaujímalo, čo s tou dĺžkou.