Mega Code Archive
Adding fields at run-time
<![CDATA[
unit Unit1;
{ This program allows fields to be added on the fly.
}
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
DB, DBTables, Grids, DBGrids, StdCtrls;
type
TForm1 = class(TForm)
Table1: TTable;
DataSource1: TDataSource;
DBGrid1: TDBGrid;
Button1: TButton;
Edit1: TEdit;
Label1: TLabel;
Label2: TLabel;
Memo1: TMemo;
procedure Button1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
begin
Memo1.Clear;
if StrComp(PChar(Edit1.Text), PChar(''))= 0 then
begin
Memo1.Lines.Add('Invalid field name');
Exit;
end
else begin
with table1 do
begin
Close; // table must be closed !!!
with FieldDefs do
begin
try
Add(Edit1.Text, ftInteger, 0, False);
Except On EDatabaseError do
begin
Memo1.Lines.Add('Error adding field ' +
Edit1.Text + ' to table.');
Memo1.Lines.Add('Maybe ''' + Edit1.Text
+ ''' already exists as a field name');
end;
end;
CreateTable;
Open;
end;
end;
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
Table1.Open;
end;
end.
]]>