MongoDB Aggregation Operations

You are not going to always return records from MongoDB but sometimes you need to perform some computations such as sum, count, average, etc. Here you need the aggregation operations which are used to process data that return the computed results. Therefore aggregation actually groups data from multiple documents and performs a variety of operations on the grouped data to return the single result. Aggregate operations retrieve a single value after performing a calculation on a set of values. Often aggregate functions are accompanied by group clause in the find()…

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MongoDB find() method with Projection

You may not want to fetch a whole bunch of data from the document which is stored in a collection in your MongoDB database. You can restrict the number of records or data using different conditions with the help of WHERE, AND, OR and IN operators, but what if you want to restrict the data you want in your particular row or record or document. So here comes the projection that helps you to selectively choose data from a record or row or document. In MongoDB, projection means selecting only…

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How to query documents – WHERE, AND, OR, IN conditions in MongoDB

MongoDB is one of the most popular NoSQL database where data are stored in the form of documents. You can also create tables in traditional way to put your structured data but the main purpose is to store unstructured data in the form of object which may vary based on a particular requirement. Now when you select data from collection, you may not need all data to be fetched from the database collection and you want to restrict those data based on certain criteria or conditions while fetching from database.…

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How to make output of MongoDB’s find() readable in shell

MongoDB is one of the most popular NoSQL database where your data are stored in a collection. To quickly access your data from MongoDB you can execute commands on MongoDB shell and your results appear based on the given criteria. One of the commands is find() function and using this command you can easily retrieve data from MongoDB collection. When you execute this find() command to retrieve data from a collection, it displays data in one line which makes it ugly and become difficult to read specially when there multiple…

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Docker Compose – Dockerizing Django MySQL App

In this tutorial I will show you how to dockerize Django MySQL app using docker compose in Linux environment. So why do you need docker compose when you have docker container? Generally it is said to be best practices when each docker container runs a process with single responsibility, but for this application you need two containers – one is for Django app and another one is for MySQL server. Therefore two containers are running independently and to establish communication between two containers you need docker compose.

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How to generate PDF report from MySQL database in Spring Boot

I am going to show yo how to download PDF file from MySQL database using Spring Boot and iText library in Java programming language. Many applications require dynamic generation of PDF documents for reporting purpose, such as, generating statements for customers, readers buying online specific chapters of a book, etc. In my another tutorial I had shown how to create or write to a PDF file using Java based iText library. The iText library is freely available and can be used using maven or gradle build tool. We can also…

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How to generate Excel Report from MySQL Database in Spring Boot

Here I am going to show you how to download excel file from MySQL using Spring framework. Generating excel report from MySQL database has few advantages over other file formats. Most of the people you are working with in your organization are familiar with excel file format, hence it needs a short learning curve. You may also like to read how to download json file in Spring Boot. The excel file has other benefits as given below: It allows you to use templates and formulas to aggregate data. It has…

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Docker Compose – Dockerizing Nodejs MySQL REST API CRUD Example

Introduction In this tutorial I am going to explain you how to use docker compose to dockerize your Nodejs MySQL REST API for CRUD operations. I am not going to tell you here how to build the REST CRUD application but you can always go back and check the detail tutorial on this here. I am only going to show you how to dockerize your app using docker compose in Linux environment. It is a best practice for a container to have only one process with single responsibility. But as…

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NodeJS Express MySQL REST API CRUD Example

Here I am going to show you how to create REST API CRUD example using Nodejs Express and MySQL server. CRUD means Create, Read, Update and Delete operations which are performed through REST (Representational State Transfer) resources that works on http/https protocol. REST resources or APIs work on verbs, such as, GET, POST, PUT, DELETE, etc. So it is obvious that GET means you need to fetch data from the server endpoint, POST means you need to create the new resource on server endpoint, PUT means you need to update…

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