How to keep searching database using Sequelize?

Question

Scenario:

1. Generate Pincode.
2. Search database whether the pincode exists.
3. If exists, go back to step 1 and step 2.
4. If does not exist, proceed to do something else. 

My code:

 var pinCode = Math.floor(1000 + Math.random() * 9000);
        db.transactionDetails.findOne({
            where: {transaction_pincode:pinCode}
        }).then(transactionDetail => {
            if(transactionDetail == null){
                db.transactionDetails.create({
                    customer_id:customerID,
                    transaction_amount:transactionAmount,
                    transaction_pincode:pinCode
                })

The code above works fine if the pincode does not exist. But how can I run the same piece of code if pincode exists ?

Answer 1

You can do that like :

function checkPincode(){
    var pinCode = Math.floor(1000 + Math.random() * 9000);
    return db.transactionDetails.findOne({
        where: {transaction_pincode:pinCode}
    }).then(transactionDetail => {
        if(transactionDetail == null){ // <------- Check if no such pincode
            return db.transactionDetails.create({
                customer_id:customerID,
                transaction_amount:transactionAmount,
                transaction_pincode:pinCode
            })
        } else {
            return checkPincode(); // <------- Call it self if pincode exists
        }
    });
}

checkPincode().then(data => { // <------ Initiate checkPincode function
    console.log(data);
});