12 Mar 2021 Tihomir Babic SQL JOIN Topics That Require Practice Are you interested in learning how to join tables in SQL? Where do you start? Many JOIN topics require practice. In this article, we’ll explore these topics by writing codes to solve real-life situations. Hopefully, you will learn which JOIN topics require attention. To make it easier for you, the topics are divided into beginner, intermediate, and advanced. Joining two or more tables in SQL lifts data analysis to another level. Read more 5 Mar 2021 Tihomir Babic How to Get Descendants of a Parent in SQL Want to learn how to handle family trees and find descendants of a parent? By reading this article, you’ll learn how to handle hierarchical data. Finding descendants from a parent is a common problem in SQL. If you imagine a family tree, the basic building block that forms the relationships within it is the parent-child relationship. The parent-child relationship is precisely what defines all hierarchical data. Another example of hierarchical data is the manager-employee relationship. Read more 12 Feb 2021 Tihomir Babic 6 Advanced SQL Queries for Analyzing Financial Data Are you an advanced SQL user who’s new to finance? Do you want to learn how to use your knowledge to analyze financial data? The article will give you some guidance. You probably know that SQL is a potent tool for analyzing all sorts of data. The bigger and more complex data, the more beneficial SQL becomes. In certain situations, financial data can be very complicated; producing a sophisticated analysis requires sophisticated tools. Read more 10 Feb 2021 Tihomir Babic Want to Learn Advanced PostgreSQL? Try This! Why and how should you learn advanced PostgreSQL? I’ll give you some tips that will help you achieve your goals. Keeping up with technology is hard; anyone who has foolishly tried to do so can confirm this (me, for example!). Most of the time, it just doesn't work. And to be brutally honest, keeping up with all the technologies all the time is pointless. You shouldn’t know everything about everything; it’s better to know as much as you need within the technology you use or want to use. Read more 1 Jan 2021 Tihomir Babic SQL JOIN Tips for Beginners If you’re a beginner and want to know how to start using SQL JOINs in your queries, you’ve come to the right place. Using the SQL JOIN clause is necessary if you want to query multiple tables. Sooner or later, you’ll have to use more than one table in a query. It’s the nature of relational databases in general – they consist of data that’s usually saved in multiple tables; in turn, these form a database. Read more 15 Dec 2020 Tihomir Babic How to Use CASE WHEN With SUM() in SQL This article will teach you what a CASE WHEN expression is in SQL and how to use it with a SUM() function and a GROUP BY statement. The examples are included to bolster your understanding. The best way to learn about CASE WHEN and how to use it with SUM() is our hands-on course Creating Basic SQL Reports. It contains over 90 interactive exercises that will teach you different techniques how to create complex reports in SQL. Read more 25 Nov 2020 Tihomir Babic How to Find All Employees Under Each Manager in SQL Have you ever been tasked with building an organizational chart – i.e. finding the employees under each manager in a company? In SQL, you can do that easier than you think! This article will show you how to get the answer using a recursive query. In the business world, it’s a very common task to list all the subordinate employees for a given manager. Is doing this hard enough to warrant a whole article? Read more 29 Oct 2020 Tihomir Babic What is the Difference Between COUNT(*), COUNT(1), COUNT(column), and COUNT(DISTINCT)? Have you noticed there are different variations of the SQL COUNT() function? This article explains the various arguments and their uses. As a SQL user, you’re probably quite familiar with the COUNT() function. Even though it’s relatively simple, it can be used in several different ways. Each way has a very different use. I imagine you’ve seen code that contains the function COUNT(*) or COUNT(1). You’ve probably also seen some other uses of the COUNT() function, such as COUNT(column name) and COUNT(DISTINCT column name), even if you haven’t used them. Read more 28 Oct 2020 Tihomir Babic What are SQL CTE Best Practices? Are you wondering what the best practices for using common table expressions are? This article will help you learn when to use a CTE and how to write it. If you have heard about SQL CTEs, you have probably noticed they’re often mentioned together with subqueries. Sometimes, people think there’s no difference compared to the subqueries, and there’s often debate about whether a CTE or subquery should be used to get a particular result. Read more 29 Sep 2020 Tihomir Babic Six Window Function Templates to Save in Your Code Editor Do you use window functions often enough to know them well but not often enough to remember all the details? Here are six window function codes you should save as templates. Window functions are a handy SQL option, but it doesn’t mean you use them all the time. Maybe you only use them occasionally; if that’s the case, you probably find yourself needing to refresh your memory every time you use them. Read more «« « 1 2 3 … 6 7 8 9 » »»