Добавление записи в базу данных SQL

procedure TMainForm.Button2Click(Sender: TObject);
 var
idassignments:integer;
query:tadoQuery;
rezult:string;
begin
if edit1.text='' then begin Edit1.SetFocus;  Edit1.SelectAll;  label7.Visible:=true; timer1.Enabled:=true; exit; end;
if maskEdit3.text='' then begin maskEdit3.SetFocus;  maskEdit3.SelectAll;  label6.Visible:=true; timer1.Enabled:=true; exit; end
else
query:= tadoQuery.Create(Self);
query.Connection:=adoConnection1;
query.SQL.Add('BEGIN TRANSACTION;');
query.SQL.Add('DECLARE @key [int];');
query.SQL.Add('INSERT INTO assignment VALUES (:document_typ,:number,:ish_number,:data_ish,:data_reg,:otpravitel,:zagolovok,:path);');
query.SQL.Add('SELECT @key = SCOPE_IDENTITY();');
query.SQL.Add('INSERT INTO correspondent VALUES (@key,:ispolnitel_correspondent,:status_correspondent,:data_isp_correspondent,:komment_correspondent);');
query.SQL.Add('INSERT INTO [dbo].[history] VALUES (:date_history,:time_history,@key,:users_history,:deystvie_history);');
query.SQL.Add('COMMIT TRANSACTION;');
 
 
if radiogroup1.ItemIndex=0 then begin query.parameters.ParamByName('document_typ').value:=1; query.parameters.ParamByName('number').value:=edit1.Text; end;
if radiogroup1.ItemIndex=1 then begin query.parameters.ParamByName('document_typ').value:=2; query.parameters.ParamByName('number').value:=edit1.Text+'-гр';    end;
if radiogroup1.ItemIndex=2 then begin query.parameters.ParamByName('document_typ').value:=3; query.parameters.ParamByName('number').value:=edit1.Text+'-сл'    end;
 
 
query.parameters.ParamByName('ish_number').value:=maskedit2.Text;
query.parameters.ParamByName('data_ish').value:=maskedit4.Text;
query.parameters.ParamByName('data_reg').value:=DateTimePicker2.Date;
query.parameters.ParamByName('otpravitel').value:= maskedit3.Text;
query.parameters.ParamByName('zagolovok').value:= memo1.Text;
query.parameters.ParamByName('path').value:='';
 
//-------------------------------------------------------------------------------------------
query.parameters.ParamByName('data_isp_correspondent').value:=datetostr(DateTimePicker3.Date);
query.parameters.ParamByName('ispolnitel_correspondent').value:=combobox2.Text;
query.parameters.ParamByName('status_correspondent').value:='В работе';
query.parameters.ParamByName('komment_correspondent').value:='';
//-------------------------------------------------------------------------------------------
query.parameters.ParamByName('date_history').value:=FormatDateTime('dd.mm.yyyy',Now);
query.parameters.ParamByName('time_history').value:=FormatDateTime('hh:nn:ss',Now);
query.parameters.ParamByName('users_history').value:=fio_glob;
query.parameters.ParamByName('deystvie_history').value:='Регистрация документа';
query.ExecSQL;