How to change the value of a variable inside mysql.query() method - mysql

Question

Here is my code.
I am new to nodejs and, I am querying to the mysql database using mysql package. I have two variables i.e. hasCouponCode and isVerifiedUser and by default they are set to false. So I want to set the value of hasCouponCode to true if the couponCode exists in db and value of isVerifiedUser to true if user exists in mysql db. But I am not able to set their values to true. Then how can I change/set its value?
app.post('/', (req, res) => {
const { name, email, couponCode } = req.body;
let hasCouponCode = false, isVerifiedUser = false;
pool.getConnection((err, connection) => {
if (err) {
throw err;
}
connection.query(`SELECT * FROM coupons WHERE couponCode='${couponCode}'`, (couponError, couponRows) => {
if (couponError) {
throw couponError;
}
if (!couponRows.length > 0) {
console.log('Coupon not found...❌');
}
console.log('Coupon found...✔️');
hasCouponCode = true;
});
connection.query(`SELECT name FROM users WHERE name='${name}'`, (userError, userRows) => {
if (userError) {
throw userError;
}
if (!userRows.length > 0) {
console.log('User not found...❌');
}
console.log('User found...✔️');
isVerifiedUser = true;
});
connection.release();
});
console.log(hasCouponCode, isVerifiedUser);
res.redirect('/');
});

Answer 1

try:
connection.query(`SELECT * FROM coupons WHERE couponCode =10`, (couponError, couponRows) => {
if (couponError) {
throw couponError;
}
if (couponRows.length) {
console.log('Coupon found...✔️');
hasCouponCode = true;
}else{
console.log('Coupon not found...❌');
}
});
connection.query(`SELECT name FROM users WHERE name='${name}'`, (userError, userRows) => {
if (userError) {
throw userError;
}
if (userRows.length) {
console.log('User found...✔️');
isVerifiedUser = true;
}else{
console.log('User not found...❌');
}
});
connection.release();