The distinct() function in MongoDB is used to retrieve distinct values. However, it has a problem. This function is a very basic function, it can only select distinct values for one field at a time. So, if there is a…
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…
Node.js can use a Date object that provides information about a timestamp. This object can be used for various purposes such as getting the current time, comparing dates, formatting dates, reminders, etc. Date objects represent a specific point in time…
MongoDB aggregation allows developers to perform complex operations while working with data stored inside a collection of a MongoDB database. One of the operations is the “group by” operation, i.e. $group, which is used to group documents based on the…
A MongoDB cluster is used to denote a replica set of a collection of datasets distributed across multiple servers to speed up the overall processing during read and write operations. In this tutorial, we will learn about clusters in MongoDB,…
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 cover the $and operator in MongoDB. So, the $and operator performs an AND operation on the given array of expressions. It eventually selects ALL the documents that matched the query. This guide aims to provide…
In this tutorial, I will discuss how to compile using Solc 0.5 in Solidity and above. Staying up to date with the latest syntax, code, methods, and techniques can be quite challenging when it comes to beginners in a programming…