MongoDB 返回一个不存在的对象

Question

我正在使用 MongoDB 和护照做一个项目，当我遇到这个错误时，虽然 p1 没有被使用，但它仍然重新运行我猜测的对象，因为它只是说字段 p1 被占用，当它不是。 p2也是如此。有谁知道为什么？

passport.use(
  "local.signup",
  new LocalStrtegy(
    {
      usernameField: "email",
      passwordField: "password",
      passReqToCallback: true,
    },
    async function (req, email, password, done) {
      req.checkBody("email", "E-mail is empty").notEmpty();
      req
        .checkBody("password", "Your password is too short!")
        .isLength({ min: 4 });
      var errors = await req.validationErrors();
      if (errors) {
        var messages = [];
        errors.forEach(function (error) {
          messages.push(error.msg);
        });
        return done(null, false, req.flash("error", messages));
      }
      const p1 = User.find({ p1: req.body.p1 });
      const p2 = User.find({ p2: req.body.p2 });

      User.findOne({ email: email }, function (err, user) {
        if (err) {
          return done(err);
        }

        if (user) {
          return done(null, false, {
            message:
              "This E-Mail alredy in use! If you believe that this is an error, please an admin on. (ERR 002 MCEE)",
          });
        } else if (p1) {
          return done(null, false, {
            message:
              "This username is alredy in use! If you believe that this is an error, please contact an admin. (ERR 002 MCEM)",
          });
        } else if (p2) {
          return done(null, false, {
            message:
              "This Tag is alredy in use! If you believe that this is an error, please contact an admin. (ERR 002 MCED)",
          });
        }

        console.log(mc + " " + dcign + " " + user);
        var newUser = new User();
        newUser.email = email;
        newUser.password = newUser.encryptPassword(req.body.password);
        newUser.p1 = req.body.p1;
        newUser.p2 = req.body.p2;
        newUser.Banned = false;
        console.log(req.body);
        newUser.save(function (err, result) {
          if (err) {
            return done(err);
          }
          return done(null, newUser);
        });
      });
    }
  )
);

Answer 1

调用 User.find 会返回一个你没有等待的 Promise。因此，当您检查 p1 和 p2 是否存在时，它会返回一个真值，因为这两个值都是 Promise 对象。

要解决这个问题，请在 User.find 前面使用 await，就像这样

const p1 = await User.find({ p1: req.body.p1 });
const p2 = await User.find({ p2: req.body.p2 });

之后，当您使用 find 方法时，这两个值都将是数组，因此只需检查长度属性或更好地使用 findOne 而不是 find 方法。

const p1 = await User.findOne({ p1: req.body.p1 });
const p2 = await User.findOne({ p2: req.body.p2 });

Answer 2

1. MongoDB .find 返回一个数组。在您的情况下， p1 是一个空数组。 if(p1) 将始终返回 true。你应该检查它的长度。
2. 您应该使用await 进行查询调用。

   const p1 = await User.find({ p1: req.body.p1 });
   const p2 = await User.find({ p2: req.body.p2 });
   

我在下面粘贴示例代码 -

passport.use(
  "local.signup",
  new LocalStrtegy(
    {
      usernameField: "email",
      passwordField: "password",
      passReqToCallback: true,
    },
    async function (req, email, password, done) {
      req.checkBody("email", "E-mail is empty").notEmpty();
      req
        .checkBody("password", "Your password is too short!")
        .isLength({ min: 4 });
      var errors = await req.validationErrors();
      if (errors) {
        var messages = [];
        errors.forEach(function (error) {
          messages.push(error.msg);
        });
        return done(null, false, req.flash("error", messages));
      }
      const p1 = await User.find({ p1: req.body.p1 });
      const p2 = await User.find({ p2: req.body.p2 });

      User.findOne({ email: email }, function (err, user) {
        if (err) {
          return done(err);
        }

        if (user) {
          return done(null, false, {
            message:
              "This E-Mail alredy in use! If you believe that this is an error, please an admin on. (ERR 002 MCEE)",
          });
        } else if (p1.length) { // Check for Length
          return done(null, false, {
            message:
              "This username is alredy in use! If you believe that this is an error, please contact an admin. (ERR 002 MCEM)",
          });
        } else if (p2.length) { // Check for Length
          return done(null, false, {
            message:
              "This Tag is alredy in use! If you believe that this is an error, please contact an admin. (ERR 002 MCED)",
          });
        }

        console.log(mc + " " + dcign + " " + user);
        var newUser = new User();
        newUser.email = email;
        newUser.password = newUser.encryptPassword(req.body.password);
        newUser.p1 = req.body.p1;
        newUser.p2 = req.body.p2;
        newUser.Banned = false;
        console.log(req.body);
        newUser.save(function (err, result) {
          if (err) {
            return done(err);
          }
          return done(null, newUser);
        });
      });
    }
  )
);