MYSQL 结果长度未定义

Question

*throw err; // Rethrow non-MySQL errors ^

TypeError: Cannot read property 'length' of undefined*

db.js:

function validateUser(username, password) {
  var sql = "SELECT * FROM users WHERE username = ? AND password = ?";
  var values = [[username, password]];
  con.query(sql,[values], function(err, results) {
    if (results.length > 0){
      return true;
    }
    else return false;

  })
}

server.js:

app.post('/auth', function(req,res) {
  console.log('form submitted');
  if(db.validateUser(req.body.username,req.body.password)){
    console.log('login successful');
  } 
  res.status(200);
  res.redirect(URL);
});

Answer 1

First please don't save passswords as plain text.

for example https://cdnjs.com/libraries/jsSHA

For your code:

function validateUser(username, password) {
  var sql = "SELECT * FROM users WHERE username = ? AND password = ?";
  var values = [username, password];
  con.query(sql,values, function(err, results) {
    if (results.length > 0){
      return true;
    }
    else return false;

  })
}