const nome = _req.getString("nome");
const email = _req.getString("email");
const telefone = _req.getString("telefone");
const pais = _req.getString("pais");

const emailExists = _db.query(
  `SELECT CASE WHEN COUNT(1) > 0 THEN TRUE ELSE FALSE END FROM cliente WHERE email = ?::varchar`,
  _val.init()
    .add(email)
  );

if (emailExists) {
  _header.status(400);
  _out.json(
    _val.map()
      .set("error",true)
      .set("message","email already exists!")
  )
};