用table控件
var newfield:Tfielddef;
begin
table1.active:=True;
newfield:=table1.fielddefs.addfielddef;
with newfield do
begin
name:='fieldname';
datatype:=ftstring;
size:=16;
required:=False;//是否必填
end;
table.active:=False;
table.createtable;
end;
用ADO,放置ADOTABLE和ADOQUERY,DATASOURCE的DATASET设为ADOTABLE
procedure TForm1.Button1Click(Sender: TObject);
begin
ADOTable1.Active := not ADOTable1.Active;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
with ADOQuery1 do
begin
Close;
SQL.Clear;
SQL.Add('Alter table MainTable Add NewField char(16)');
Prepared;
ExecSQL;
end;
end;