Express JS query Error Handling not working-CodePudding

this is my first post on Stackoverflow, so please be kind.

I have a huge problem, which I couldn't fix by googling (which is pretty rare). I want to create a simple error handling in my query, but it won't work.

Here's the code:

pool.query("SELECT password_hash FROM User WHERE email = ?",
    req.body.EMailLogin, (error, results, fields) => {
      
      if(error) {
        // It executes the if aswell as the else statement and I dont know why (if(error) seems to be ignored even if its true)
      } else {
        // And then it crashes here, because password_hash is undefined
        let hash = results[0].password_hash;
        bcrypt.compare(req.body.PasswordLogin, hash, function(err, result) {
          if (result == true) {
            ses.user = req.body.EMailLogin;
            req.session.cookie.expires = false;
            req.session.save(() => {
              return res.redirect('/index');
            });
          } else {
            res.render(); // My Page for Wrong Password (ignore this)
          }
        });
      }
    }
  );

CodePudding user response：

You need to throw the err inside the if

if(error) {
        throw error;
      } else {

And I think that the error is how you're passing the parameter, it should be an array:

pool.query("SELECT password_hash FROM User WHERE email = ?",
    [req.body.EMailLogin],

I hope this fixes your problem.

CodePudding user response：

You missed to check weather query return data or not and also you can pass values either using object or array(in your case, should be array)

pool.query("SELECT password_hash FROM User WHERE email = ?", [req.body.EMailLogin],
    (error, results, fields) => {
        if (error) {
            // any error like wrong query, connection closed, etc.
            // It executes the if aswell as the else statement and I dont know why (if(error) seems to be ignored even if its true)
        } else if (results.length === 0) {
            // email not found in database
            // My Page for Wrong Email ???
        }   else {
            // And then it crashes here, because password_hash is undefined
            let hash = results[0].password_hash;
            bcrypt.compare(req.body.PasswordLogin, hash, function (err, result) {
                if (result == true) {
                    ses.user = req.body.EMailLogin;
                    req.session.cookie.expires = false;
                    req.session.save(() => {
                        return res.redirect('/index');
                    });
                } else {
                    res.render(); // My Page for Wrong Password (ignore this)
                }
            });
        }
    }
);