How to check user name and password via NodeJs and sqlite? - node.js

Question

I'm trying to check user name and password (which I'm getting via post) and if it correct, response with the user page.
for some reason I'm always fail (although I know the user and pass are correct):
app.post("/loginDetials", function(req, res) {
var userName = req.body.userName;
var passw = req.body.passw;
if(req.body.userName && req.body.passw)
{
console.log('Checkking userName: ' + userName + ' password: ' + passw);
var db = new sqlite3.Database('usersDataBase');
db.all("SELECT * FROM usersTable where (userName==?) AND (password==?)", function(err,rows){
if (err)
{
console.log('Error: ' + err);
}
else
{
rows.forEach(function (row) {
console.log('Login Succ')
res.sendFile('userSite.html', {root: __dirname })
});
}
});
db.close();
}
console.log('Login Fail')
res.sendFile('main.html', {root: __dirname })
});
What am I doing wrong ?
And is this the correct way to verify details ?

Answer 1

You have some async code and other flow problems with your code.
You are actually sending twice your response and you close the database before the query has been executed.
Problem with calling twice res.send
var userName = req.body.userName;
var passw = req.body.passw;
if(req.body.userName && req.body.passw) {
/** Some logic */
res.send(...);
}
res.send(...);
So you see res.send is called twice if you have supplied userName and passw query.
Problem with async closing db connection
In JavaScript we have async functions which don't stop the flow of the program and rely on callbacks. db.all is such a function, which you call and immediately after that you call db.close()
var db = new sqlite3.Database('usersDataBase');
db.all("SELECT * FROM usersTable where (userName==?) AND (password==?)", function(err,rows){
// You need to move your `db.close()` inside the callback
// in order to close the database when the query has ended
db.close();
if (err)
{
console.log('Error: ' + err);
}
else
{
rows.forEach(function (row) {
console.log('Login Succ')
res.sendFile('userSite.html', {root: __dirname })
});
}
});
// db.close(); <-- commented out.