How to Make Discount coupon codes in NodeJs & MongoDb

by Negative Space @ pexels

Maybe you would like to build a discount system for your online store or platform. In the first look, It seems a little scary and complicated, but it’s so easy in NodeJs/MongoDB based systems!
First of all, You need to add a discount model to your model’s folder in your product ready nodeJs project:

var mongoose = require(‘mongoose’);
var connection = mongoose.createConnection(“mongodb://localhost/{customName}”);
var DiscountCodesSchema = mongoose.Schema(
{code: { type: String, require: true, unique: true },
isPercent: { type: Boolean, require: true, default: true },
amount: { type: Number, required: true } // if is percent, then number must be ≤ 100, else it’s amount of discount
expireDate: { type: String, require: true, default: ‘’ },
isActive: { type: Boolean, require: true, default: true }
});
DiscountCodesSchema.pre(‘save’, function (next) {
var currentDate = new Date();
this.updated_at = currentDate;
if (!this.created_at) {
this.created_at = currentDate;
}
next();
});
var Discounts = mongoose.model(‘DiscountCodes’, DiscountCodesSchema);
module.exports = Discounts;

Then, you need to make a random code generator for making discount coupon codes, For this step, I prefer to make a separate module and save my function in it:

function coupongenerator() {
var coupon = “”;
var possible = “abcdefghijklmnopqrstuvwxyz0123456789”;
for (var i = 0; i < {custom code length in here}; i++) {
coupon += possible.charAt(Math.floor(Math.random() * possible.length));
}
return coupon;
}
module.exports = coupongenerator;

Then, We can easily use it in our API route. BUT before than saving generated code, you need to check if code is existing, Make a new one:

…
let isExistDiscount = false
do {
let myDiscountCode = coupongenerator()
let newDiscountCode = new DiscountCode({
code: myDiscountCode,
isPercent: false,
amount: [{ IRT: 5000 }, { USD: 5 }, { EUR: 5 }],
expireDate: ‘’,
isActive: true
})
newDiscountCode.save(function (err) {
if (err) {
if (err.name === ‘MongoError’ && err.code === 11000) {
// Duplicate code detected
isExistDiscount = true;
}
}
res.send({
//success message render
})
})
}
while (isExistDiscount);
…

And finally, you can use the discount coupon code field in anywhere check and process it from MongoDB.

Good luck!

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