dataBaseConector.checkUser = async (data) => {
  try {
    const sql = 'SELECT * FROM users WHERE user_login = ' + mysql.escape(data.login) + 'AND user_pass = ' + mysql.escape(data.pass);

    const con = await connectionSetter;
    const itemData = await con.query(sql);

    if (itemData.length === 0) throw { status: 404, message: 'User doesnt exist' };
    return { status: 200, message: 'User exists.' }
  }
  catch (err) {
    if (err.status === 404) {
      throw { status: 404, message: 'User doesnt exist' }
    }
    else throw { status: err.sqlState, message: err.sqlMessage };
  };
};