Доступ к базам через FireDAC

// Определите реальную гарантию в FireDacConnection.
program FireDacConnection;
{$APPTYPE CONSOLE}
uses FireDAC.Comp.Client, FireDAC.Phys.SQLite;
var
  Conn: TFDConnection;
begin
  Conn := TFDConnection.Create(nil);
  try
    Conn.Params.Values['DriverID'] := 'SQLite';
    Conn.Params.Values['Database'] := ':memory:';
    Conn.Connected := True;
  finally Conn.Free; end;
end.

// Отделите правило языка от удачного запуска DatasetState.
program DatasetState;
{$APPTYPE CONSOLE}
uses FireDAC.Comp.Client, Data.DB;
procedure RefreshOrders(Q: TFDQuery);
begin
  if Q.State in dsEditModes then
    Q.Post;
  if Q.Active then
    Q.Refresh
  else
    Q.Open;
end;
begin end.

// Определите реальную гарантию в TransactionFlow.
program TransactionFlow;
{$APPTYPE CONSOLE}
uses FireDAC.Comp.Client;
procedure Transfer(Conn: TFDConnection; A, B: Integer; Sum: Currency);
begin
  Conn.StartTransaction;
  try
    Conn.ExecSQL('update accounts set balance = balance - :s where id = :id', [Sum, A]);
    Conn.ExecSQL('update accounts set balance = balance + :s where id = :id', [Sum, B]);
    Conn.Commit;
  except
    if Conn.InTransaction then
      Conn.Rollback;
    raise;
  end;
end;
begin end.

// Отделите правило языка от удачного запуска SqlParameters.
program SqlParameters;
{$APPTYPE CONSOLE}
uses FireDAC.Comp.Client;
procedure FindUser(Q: TFDQuery; const Login: string);
begin
  Q.SQL.Text := 'select id, name from users where login = :login';
  Q.ParamByName('login').AsString := Login;
  Q.Open;
end;
begin end.

// UPDATE выполняется через ExecSQL на настроенном соединении.
program QueryModes;
{$APPTYPE CONSOLE}
uses FireDAC.Comp.Client, FireDAC.Phys.SQLite, System.SysUtils;
var
  Conn: TFDConnection;
  Q: TFDQuery;
begin
  Conn := TFDConnection.Create(nil);
  Q := TFDQuery.Create(nil);
  try
    Conn.Params.Values['DriverID'] := 'SQLite';
    Conn.Params.Values['Database'] := ':memory:';
    Conn.Connected := True;
    Conn.ExecSQL('create table items (active integer, expires_at timestamp)');
    Conn.ExecSQL('insert into items values (1, :expires)', [Now - 1]);

    Q.Connection := Conn;
    Q.SQL.Text := 'update items set active = 0 where expires_at < :now';
    Q.ParamByName('now').AsDateTime := Now;
    Q.ExecSQL;
    Writeln(Q.RowsAffected);
  finally
    Q.Free;
    Conn.Free;
  end;
end.