MongoDB: $group aggregation in Java

In this post, we will learn to use a simple way to use MongoDB $group aggregation in Java. First, we will learn to use it in MongoDB itself then try to use that aggregation pipeline in Java. Let’s analyze a MongoDB document in a reports collection which is given below: There are many documents in reports collection. We… Read More »

Array Operator in MongoDB

The array operator in MongoDB is used to query for array fields. We’ve other fields type like String, Numeric and Boolean values. These are common types and have the same kind of implementation. But the Array is a little different than others. We will be learning common use cases and implementation of the Array operators here. Most frequently… Read More »

MongoDB: $expr Expressive Query Operator

$expr operator in MongoDB is an Expressive Query Operator. It does more than the single operator like $and and $or. It allows the use of aggregation expressions within the query language. The syntax of $expr operator is given below: It also allows us to use variables and conditional statements. Let’s see an example of this. In our previous… Read More »

How To Make WordPress Admin Dashboard Faster?

This post will explain how to make the WordPress admin dashboard faster. There could be a number of reasons why it is slow. However, the common reason is probably the same for everyone. Most of the websites use Cloudflare. There is no doubt that the default setting of Cloudflare works perfectly. Sometimes it causes a problem like slowness… Read More »

Difference Between JDK, JRE and JVM

The three components of Java are JDK, JRE, and JVM. In this post, we will learn each of them in detail. JDK JDK stands for Java Development Kit. It consists of all the tools that are needed to develop Java applications. JDK is platform dependent. Hence, we need to download it for each platform. There are different JDK… Read More »

Why Java Is Platform Independent?

Before directly jumping to the reason first, we must understand how Java actually works and what are the component available in Java. So that we can easily understand why Java is platform independent. We all know that Java is a widely used programming language and probably, it is the first choice of large enterprise companies for the last… Read More »

Logical Operator in MongoDB

A logical operator is a word or a function that can be used to compare two or more expressions so that the compounded result will return the boolean value. MongoDB supports the standard set of four Logical Operators that we already know in our programming language like Java. Following are the available logical operators in MongoDB. Operator Description… Read More »

Comparison Operator in MongoDB

In this post, we will learn some comparison operator in MongoDB. The comparison operator in MongoDB can be used to return the data based on the value comparison in the fields. The equivalent of Java can be read in this post. The syntax of using the comparison operator in MongoDb is: The comparison operator in MongoDB are: Name… Read More »

Delete in MongoDB

In this post, we will learn to use the delete command in MongoDB. As we all know, having a delete functionality is very important in any system so that we can remove unwanted data when required. Delete MongoDB Collection To delete a collection in MongoDB we can use a drop() method. Syntax: Example: To delete a collection first… Read More »

Update MongoDB Document

In this post, we will learn to update a MongoDB Document. Update functionality is very important in every field so as in the MongoDB document. In MongoDB, we use the following two methods to update a MongoDB Document. updateOne() and updateMany() updateOne() MongoDB document The updateOne() method updates a single document that matches the filter criteria. The filter… Read More »