begin
showmessage('已经存在相同的学号!');
edit1.SetFocus;
end;
end;
删除学生信息的窗体：
procedure TForm_infos_del.Button3Click(Sender: TObject);
begin
if RadioButton1.Checked then
begin
if edit1.Text='' then
begin
showmessage('请填写学号!');
edit1.SetFocus;
end
else
if MessageDlg('确认删除'+edit1.Text,mtConfirmation,mbOkCancel,0)=mrOk then
begin
query1.Close;
query1.SQL.Clear;
query1.SQL.Add('delete from student where sno=:sno');
query1.ParamByName('sno').AsString:=edit1.Text;
query1.ExecSQL;
query2.ParamByName('Num_room').AsString:=Num_room;
query2.ExecSQL;
edit1.Text:='';
end;
end;
if RadioButton3.Checked then
begin
if edit2.Text='' then
begin
showmessage('请填写寝室号!');
edit2.SetFocus;
end
else
if edit3.Text='' then
begin
showmessage('请填写床位号!');
edit3.SetFocus;
end
else
if MessageDlg('确认删除?',mtConfirmation,mbOkCancel,0)=mrOk then
begin
query1.Close;
query1.SQL.Clear;
query1.SQL.Add('delete from student where Num_room=:Num_room and Num_bed=:Num_bed');
query1.ParamByName('Num_room').AsString:=edit2.Text;
query1.ParamByName('Num_bed').AsString:=edit3.Text;
query1.ExecSQL;
&nbs
