In this article, I will explain how to use mappings inside structs in Solidity. This guide will explain what are mappings in Solidity and how to use them structs. We will also learn what structs are in the world of…
In this guide, I will discuss how to get the timestamp in Nodejs in its different forms. We can use timestamps in our applications to, for instance, inform users about when an activity was performed. In this guide, I will…
In this tutorial, we will discuss the MongoDB select, count, and group by aggregate stages. The aggregate count and group stage together return the number of documents in a group. We will see an example for this topic in this…
In this tutorial, we will be discussing the node-fetch module for Node.js. When developing a web application, we do not really build everything from scratch. We might want to sometimes “outsource” a few tasks. For this, we can make use…
In this tutorial, I will discuss what is a cluster in MongoDB. I will also discuss the different types of clusters. In MongoDB, we use the word “cluster” to denote either a replica set or a sharded cluster. We will…
In this tutorial, we will learn about sharding in MongoDB. It is time we learn an intermediate-level topic. Sharding in MongoDB is one such topic. Now, sharding in layman’s terms means that mechanism that stores data on multiple machines. This…
In this article, I will explain how to solve transaction errors in Solidity. This guide aims to provide examples of how to solve transaction errors in Solidity. So, let us get this guide started. The Transaction Error in Solidity A…
In this tutorial, I will teach you how to perform error testing for your smart contract in Solidity. Error testing is a crucial aspect of development especially when it comes to blockchain development. Unlike development using other technologies, blockchain technology…
In this tutorial, I will help you find records where array field is not empty in MongoDB. We will learn different ways to find records where array field is not empty in MongoDB. This guide aims to provide examples to…
A MongoDB database has multiple collections. These collections can store millions of documents(data in MongoDB is called a document). MongoDB has various methods to fetch the documents from a collection such as find(), findOne(), findOneAndUpdate(), etc. We already have covered…