email verification from database using express js node js and angular 6 with mysql database - mysql

Question

i am creating a user, with 'email' field so i want to verify whether that email is already exist or not, if exists error must display. i have my code in express js, node js, angular 6 and mysql database and below is the code to create new user
exports.create = (req, res) => {
// Save to MySQL database
let customer = req.body;
Customer.create(customer).then(result => {
// Send created customer to client
res.json(result);
});
};
where should i use if statement in above code
Thanks in advance

Answer 1

I'm thinking the simplest way of solving your problem is making the email column in the database unique. If you try to insert a new user with an already existing email the query will fail.
Another solution would be that you first do a query that looks in the database if an already existing user has the email (from req.body.email). But that would require having two different SQL queries, which I personally would not prefer.

Answer 2

i think you are using Sequelize ORM.
You can do like this
Customer.findOrCreate({
where: {
email: req.body.email,
},
// other datas needs to inserted
defaults: {
name: req.body.name,
username: req.body.username,
},
}).spread((data, created) => {
if (created) {
// your logics
} else {
res.status(400).send(`${req.body.email} already exists.`);
}
});