Node js + Multiple query transaction + Affiliate API data insert into postgresql database - node.js

Question

Now i am working with Flipkart affiliate API and get the categories and products insert into my database.
I am using nodejs backend and postgresql database.
I used 4 async loop. But I done something but don't know the correct approach. Here I want to execute the loops in asynchronous and once all the process(loops) end means need to send response. How to I determine the all loops executed successfully. Please anyone suggest the correct approach.
var request = require('request');
var dateFormat = require('date-format');
var async = require('async');
router.get('/getproducts', function(req, res) {
var affiliateIdFrom = 1;
var affiliateUrl = "https://affiliate-api.flipkart.net/affiliate/api/<your affiliate_tracking_id>.json";
request(affiliateUrl, function(error, response, html) {
var resData = JSON.parse(html);
var dataObj = resData.apiGroups.affiliate.apiListings;
async.each(Object.keys(dataObj), function(item, done) {
var objData = dataObj[item].availableVariants['v0.1.0'];
var cname = objData.resourceName;
var curl = objData.get;
client.query('INSERT into product_category (affiliate_from, name, url,created_on) values (' + "'" + affiliateIdFrom + "'" + ',' + "'" + cname + "'" + ',' + "'" + curl + "'" + ',' + "'" + today + "'" + ')', function(err, result) {
if (err) {
console.log(err);
res.send({
data : "Soemthing went wrong",
});
}
done(err, result);
});
}, function(err) {
product.getProductDetails(affiliateIdFrom);
});
});
});
var product = {
getProductDetails : function(aId) {
var today = dateFormat(new Date());
client.query("select * from product_category where affiliate_from = " + aId + " limit 1", function(err, result) {
if (err) {
console.log(err);
}
var categoryList = result.rows;
async.each(categoryList, function(value, done) {
request.get({
headers : {
'Fk-Affiliate-Id' : 'XXXXX',
'Fk-Affiliate-Token' : 'XXXXXXXXXXXXXXXXXXXXXXX'
},
url : value.url
}, function(error, response, body) {
var data = JSON.parse(body);
var dataLength = data.productInfoList.length;
var dataObj = data.productInfoList;
if (dataLength > 0) {
async.each(dataObj, function(value1, done1) {
var productBasicInfo = value1.productBaseInfo.productIdentifier;
var productId = productBasicInfo.productId;
var productDetails = value1.productBaseInfo.productAttributes;
var pTitle = productDetails.title;
var thumbnailUrl = JSON.stringify(productDetails.imageUrls);
var category = productBasicInfo.categoryPaths.categoryPath[0][0].title;
var mrp = productDetails.maximumRetailPrice.amount;
var price = productDetails.sellingPrice.amount;
var prodcutUrl = productDetails.productUrl;
var productDescription = productDetails.productDescription;
if (productDescription != null) {
productDescription = productDescription.replace(/'/g, "\''");
}
var inStock = productDetails.inStock;
var information = JSON.stringify(value1);
var q = 'insert into product(affiliate_from, title, image_url, category_paths, mrp, price, url, description, in_stock, information, created_on) values (' + "'" + aId + "'" + ', ' + "'" + pTitle + "'" + ', ' + "'" + thumbnailUrl + "'" + ', ' + "'" + category + "'" + ', ' + "'" + mrp + "'" + ', ' + "'" + price + "'" + ', ' + "'" + prodcutUrl + "'" + ', ' + "'" + productDescription + "'" + ', ' + "'" + inStock + "'" + ', ' + "'" + information + "'" + ', ' + "'" + today + "'" + ' )';
console.log(q);
client.query(q, function(err, result) {
if (err) {
console.log(err);
} else {
console.log('inserted successfully');
}
});
done1("err", "result");
}, function(err) {
console.log('dddddddddd');
});
}
//console.log(data.productInfoList);
console.log(data.productInfoList.length);
done(err, "result");
});
}, function(err) {
console.log('doneeeeee');
});
});
}
};

Answer 1

The correct approach is to place each of your asynchronous requests inside a transaction, which when finished, will give you the indication of whether the whole set of queries was successful or not.
For example, using pg-promise syntax, your transaction would like this:
db.tx(function () {
return promise.all([
this.query("insert 1 ..."),
this.query("insert 2 ..."),
this.query("insert 3 ...")
]);
})
.then(function (data) {
// success;
}, function (reason) {
// error
});