Overview Subquery is a powerful SQL tool. It enables users to do things that are not possible using common statements. Here are some common use cases of subqueries: In this post, I will show you how to use subqueries to get the data you need from your tables. Let’s get started. A Simple (and useless) … Read more
Overview Now you have your data populated (if you haven’t, please go back to the previous post) to complete the setup. In this post, I’m going to show you various way to query your data using the SELECT command. When using in combination with other clauses (such as WHERE, LIMIT), you can get exactly what … Read more
Introduction PostgreSQL provides a variety of built-in aggregation functions that allow you to calculate values such as count, sum, average, minimum, and maximum values for a set of rows. In this post, I’m going to walk you through the basic to advance aggregation functions. Let’s get started Basic Aggregation Functions You can use aggregation functions … Read more
Overview In this post, I will walk you through the setup of your environment and data so you can start quickly. As in the series introduction, I said that we will use PostgreSQL. The quickest way to set up a PostgreSQL database instance is by using docker-compose. Setting up PostgreSQL using docker-compose You can use … Read more