为Table添加删除固定字段解决思路

为Table添加删除固定字段
在程序运行中想添加删除Table中的固定字段，如何操作啊
谢谢

------解决方案--------------------
ALTER TABLE table_name
ADD column_name datatype

ALTER TABLE table_name
DROP COLUMN column_name


http://www.w3schools.com/sql/sql_alter.asp
------解决方案--------------------
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(IntToStr(ADOQuery1.Fields.Count));
ADOQuery1.Fields.Remove(ADOQuery1F_ID);//这里面是你的字段的名字
ShowMessage(IntToStr(ADOQuery1.Fields.Count));
DBGrid1.DataSource:=nil;
DBGrid1.DataSource:=DataSource1;
end;
------解决方案--------------------
unit Unit1;

interface

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

type
TForm1 = class(TForm)
ADOConnection1: TADOConnection;
ADOQuery1: TADOQuery;
DataSource1: TDataSource;
DBGrid1: TDBGrid;
Button1: TButton;
Button2: TButton;
ADOQuery1F_ID: TStringField;
ADOQuery1F_RYID: TStringField;
ADOQuery1F_NAME: TStringField;
ADOQuery1F_USER: TStringField;
ADOQuery1F_PASS: TStringField;
ADOQuery1F_DATE: TStringField;
ADOQuery1F_TIME: TStringField;
ADOQuery1F_SY: TStringField;
ADOQuery1F_ORDER: TIntegerField;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
//删除
//ShowMessage(IntToStr(ADOQuery1.Fields.Count));
ADOQuery1.Fields.Remove(ADOQuery1F_ID);//这里面是你的字段的名字
//ShowMessage(IntToStr(ADOQuery1.Fields.Count));
DBGrid1.DataSource:=nil;
DBGrid1.DataSource:=DataSource1;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
//添加
ADOQuery1.Fields.Add(ADOQuery1F_ID);
DBGrid1.DataSource:=nil;
DBGrid1.DataSource:=DataSource1;
end;

end.
这是全部代码,另外,你需要自己创建 ADOQuery1F_ID 对象,然后添加