viniciussanchez

begin
  qryUsuarios.SQL.Clear;
  qryUsuarios.SQL.Add('select *');
  qryUsuarios.SQL.Add('  from user');
  qryUsuarios.SQL.Add(' where login = ' + QuotedStr(edtUsuario.Text));
  qryUsuarios.SQL.Add('   and password = ' + edtSenha.Text);
  qryUsuarios.Open();
  if qryUsuarios.IsEmpty then
    ShowMessage('ERRO!!!')
  else

viniciussanchez

CREATE TABLE User (
    ID       INTEGER PRIMARY KEY NOT NULL,
    NAME     VARCHAR (100),
    LOGIN    VARCHAR (20) NOT NULL,
    PASSWORD INTEGER NOT NULL
);

viniciussanchez

type
  TVenda = record
    Valor: Currency;
    QuantidadeItensVendidos: Integer;
    class operator Equal(AVenda1, AVenda2: TVenda): Boolean;
  end;
  
var
  LVenda1, LVenda2: TVenda;
begin

viniciussanchez

type
  TVenda = record
    QuantidadeItensVendidos: Integer;
    class operator Inc(AVenda: TVenda): TVenda;
  end;
  
var
  LVenda: TVenda;
begin
  LVenda.QuantidadeItensVendidos := 10;

viniciussanchez

type
  TVenda = record
    Valor: Currency;
    class operator Implicit(AValor: string): TVenda;
  end;

var
  LVenda: TVenda;
begin
  LVenda := '300';

viniciussanchez

var
  LVenda: TVenda;
begin
  LVenda.Valor := StrToCurr('300');
end;

viniciussanchez

var
  LVenda1, LVenda2: TVenda;
begin
  LVenda1.Valor := 100;
  LVenda2.Valor := 50;
  ShowMessage(CurrToStr(LVenda1.Valor + LVenda2.Valor));
end;

viniciussanchez

type
  TVenda = record
    Valor: Currency;
  end;

viniciussanchez

type
  TVenda = record
    Valor: Currency;
    class operator Add(AVenda1, AVenda2: TVenda): Currency;
  end;

var
  LVenda1, LVenda2: TVenda;
begin
  LVenda1.Valor := 100;

viniciussanchez

unit Solid.DIP.Correcao;

interface

type
  IConnection = interface
    ['{9C68D361-8374-443A-AC99-80EEF63F9BE6}']
    procedure Connect;
  end;