adoquery1.SQL.Add(' select * from productcode where id like :cpbh ');
adoquery1.Parameters.ParamByName('cpbh').Value:='%'+trim(edit_cpbh.Text)+'%';
adoquery1.Open;
procedure TForm1.Button3Click(Sender: TObject);
begin
adoquery1.Close;
adoquery1.sql.Clear;
adoquery1.Parameters.ParamByName('cpbh').Value:=edit_cpbh.Text;
adoquery1.SQL.Add(' select * from productcode where id like '':cpbh%'' ');
adoquery1.Open;
end;