What Does ORDER BY Do? by Kateryna Koidan 9 Feb 2021 When analyzing data, it often helps to have rows ordered in a specific way. In this article, I’ll use multiple examples to show how SQL ORDER BY sorts data according to one or more columns in ascending or descending order. Introduction to ORDER BY By default, the order of rows in the output of an SQL query is arbitrary. If you want to sort the output in a particular order, you’ll need to use the ORDER BY keyword. Read more GROUP BY in SQL Explained by Kateryna Koidan 15 Sep 2020 The SQL GROUP BY statement is easy to use, but it can be hard to master. Learn what you can do with GROUP BY, how it works, and how to use it with aggregate functions. GROUP BY is one of the basic SQL tools. However, it might be difficult for beginners to understand how GROUP BY works and how it is used to compute statistics with different aggregate functions. In this article, I’ll use several examples to show exactly how GROUP BY organizes rows and how aggregate functions can be used to calculate statistics on one or more columns. Read more How to Find Duplicate Values in SQL by Zahin Rahman 2 Sep 2020 Duplicate records waste time, space, and money. Learn how to find and fix duplicate values using SQL’s GROUP BY and HAVING clauses. Database best practices usually dictate having unique constraints (such as the primary key) on a table to prevent the duplication of rows when data is extracted and consolidated. However, you may find yourself working on a dataset with duplicate rows. This could be because of human error, an application bug, or uncleaned data that’s been extracted and merged from external sources, among other things. Read more How ORDER BY and NULL Work Together in SQL by Kateryna Koidan 30 Jun 2020 Do NULL values come first or last when you use ORDER BY? Are they considered higher or lower than non-NULL values? In this article, I’ll explain how different relational databases treat NULL values when sorting output and how to change the default behavior of the ORDER BY clause. When LearnSQL users practice the ORDER BY clause in our SQL Basics course, they often ask why NULL values appear first in the output and how they can change this behavior. Read more Difference between GROUP BY and ORDER BY in Simple Words by Shanika Wickramasinghe 10 Dec 2019 For someone who is learning SQL, one of the most common places to get stuck is when learning the GROUP BY command. GROUP BY and ORDER BY are two important keywords in SQL that we use to organize data. The difference between GROUP BY and ORDER BY is that ORDER BY is more simple than GROUP BY and is usually introduced early in an SQL course. Sometimes, people are quite confused over these two concepts (SQL ORDER BY vs. Read more How to Sort Records with the ORDER BY Clause by Dorota Wdzięczna 18 May 2017 Relational databases don't store records in alphabetical, numerical, ascending, or in any particular order. The only way to order records in the result set is to use the ORDER BY clause. You can use this clause to order rows by a column, a list of columns, or an expression. You can also order rows using the CASE expression. In this post, we'll take a look at the ORDER BY clause – how to write it, how it works, and what it does. Read more