unable to return response after login in node js api - mysql

Question

TypeError: res.send is not a function.
I am getting this error when I try to return response after user login successfully.
can anybody help me out from this error.
here is my code:-
exports.login = function(req, res, next) {
let q = "SELECT * from users WHERE email = ?";
let query = sql.query(q,req.body.email, (error, res) => {
if (res.length > 0) {
bcrypt.compare(req.body.password, res[0].password, function(err, result){
if(err) {
console.log('password dost not match');
console.log("error: ", err);
result(null, err);
}
if(result) {
console.log('pasword match');
const jwtToken = jwt.sign({
email: res[0].email,
id: res[0].id
},
'secret',
{
expiresIn: '2h'
});
//tk = jwtToken;
return res.status(200).json({
error:0,
message:'user login successfully',
token:jwtToken
});
}
});
} else {
console.log('error commit');
console.log("error: ", error);
result(null, error);
}
});
};

Answer 1

just change the res from the call back of sq.query to dataResult, because once you send the res.send... then for sure in your case res was the dataResult of the sql.
exports.login = function(req, res, next) {
let q = "SELECT * from users WHERE email = ?";
let query = sql.query(q,req.body.email, (error, dataResult) => {
if(error){
console.log('error commit');
console.log("error: ", error);
res.status(400).send({error});
}
if (dataResult && dataResult.length > 0) {
bcrypt.compare(req.body.password, dataResult[0].password,
function(err, result){
if(err) {
console.log('password dost not match');
console.log("error: ", err);
res.status(400).send({err});
}
if(result) {
console.log('pasword match');
const jwtToken = jwt.sign({
email: dataResult[0].email,
id: dataResult[0].id
},
'secret',
{
expiresIn: '2h'
});
//tk = jwtToken;
return res.status(200).json({
error:0,
message:'user login successfully',
token:jwtToken
});
}
}else{
res.status(400).send({error:'error occured no email
found'});
}
});
});
};