19 Top SQL Articles for Beginners Published in 2019

In 2019, a lot of new SQL articles were written for beginners. This kind of resource is useful not only for professionals. SQL articles allow you to develop skills, expand your knowledge, and use SQL in practice. They are a very good way to learn SQL. In this post, I gathered 19 top SQL articles of 2019. Let’s also learn SQL from articles!

List of Top SQL Articles Published in 2019

We will start with five of the best articles published on the LearnSQL.com platform. The articles are listed according to the level of difficulty.

1. “8 Most Common Programming Errors Made by Beginners” by Magdalena Wojtas

You know, beginners in SQL are not the only ones making mistakes in the code. It is good practice to avoid typical mistakes at the start of learning SQL.

The author of this article presents 8 basic rules to help you write better code, which saves a lot of frustration, especially for a novice SQL programmer. You find out how to write code, why is it worth it to make backups, and where to find solutions to hard problems.

2. "Order of SQL Operations" by Ignacio L. Bisso

SQL is the language in which you have to write a query according to a determined order of operations. This article shows the six main clauses (SELECT, FROM, WHERE, GROUP BY, HAVING, ORDER BY) and presents examples to show the proper clause order in the query. The author explains in detail how the query is then executed by the database. It is a fantastic SQL article for beginners who are learning to write correct SQL queries.

3. "SQL INNER JOIN Explained in Simple Words" by Ignacio L. Bisso

This SQL article covers an issue with one of the JOIN clauses: INNER JOIN – the most popular JOIN statement used in SQL queries. The author gives you a lot of specific information about this kind of JOIN.

At the beginning of this SQL article, an example database is presented, followed by details about each part of the INNER JOIN query. At the end of the article, the author gives you advice on how to continue learning about JOINs.

4. “The Most Important SQL Queries for Beginners” by Dorota Wdzięczna

Even at the start of SQL learning, it is important to review SQL knowledge from time to time.

This SQL article provides a list of most commonly used SQL queries. You should know them. This overview allows to find you a given query very fast. The author presents 30 useful kinds of SQL queries. It is a good SQL queries guide, especially for beginners.

5. "Grouping Data in SQL Server" by Belma Mesihovic

The SQL language can help you group data. In this post, you will learn the syntax of the GROUP BY clause and find out how to use it. You will also obtain knowledge about how to group data according to aggregate values.

The author in this SQL article presents practical tasks with solutions, explanation, and analyzed queries. The examples are basic so it is a good guide, especially for beginners in SQL Server.

6. “Empty Thoughts: Working with NULL” by Joe Celko

This post considers the ways in which the SQL Server database system handles NULLs in various types of SQL queries. At the beginning of this SQL article, the author explains the meaning of a NULL. In the following paragraphs, he presents the three-value logic (TRUE, FALSE, UNKNOWN) of NULL and the results of comparing a NULL with others values, including another NULL.

In other parts of this guide, you learn about NULLs in DDL statements; NULLs in DML statements; grouping NULLs; how NULL works with set operators like UNION, INTERSECT, EXCEPT; and how to use NULL with OUTER JOIN.

Besides all of this, you learn how to avoid NULLs in SQL queries.

This SQL article is a great source to learn SQL, not only for beginners in SQL.

7. “SQL multiple joins for beginners with examples” by Esat Erkec

If you are a beginner in SQL, you have to learn the SQL multiple joins concept. JOINs operators are used very often in SQL queries. Maybe this is not the easiest material for students starting to learn SQL, but this SQL article explains it simply with a lot of examples and illustrations. The author Esat Erkec considers a basic concept of JOIN, shows how to join tables with four basic JOINs operators, and shows the differences in types of multiple joins. At the end of the article, you will find a quiz with answers.

8. “Database Fundamentals #24: Filtering Data” by Grant Fritchey

One of the fundamental concepts in SQL querying is filtering data in the result set. In this SQL article, the author considers operators used in the WHERE clause and shows how to use them. The examples illustrate ways to correctly filter using queries. It is an especially good source for beginners in SQL.

9. “CTE With (INSERT/ DELETE/ UPDATE) Statement In SQL Server” by Vishwanath Dalvi

Common Table Expression called CTE is a structure of SQL that allows programmers to simplify complex logic and write reusable and easy-to-read SQL queries. Therefore, it is an important concept worth learning. The author explains the CTE syntax step-by-step and presents examples and details on how to use it in various statements like SELECT, INSERT, DELETE, MERGE, and UPDATE.

Good source for beginners in SQL and more advanced SQL learners.

10. “A beginner’s guide to SQL CROSS JOIN” by Vlad Mihalcea

Do you know what CROSS JOIN is for? This post explains what it is and how to use this type of JOIN in a SQL query. Using the example database, the author shows styles of the CROSS JOIN. He also presents queries using this type of JOIN in different database systems. This guide would support SQL beginners,teachers of SQL, and advanced SQL programmers.

11. “Ten SQL Commands You Should Be Using” by Hannes DuPreez

The next SQL article published in 2019 worth your attention is the set of ten popular SQL commands. The author in his guide presents the list of SQL statements that you should know, because they are used very often and help you to operate on the database. You find in this list both definition and manipulation types of commands. It is mandatory material presented in a short description for students learning SQL.

12. “MySQL vs PostgreSQL -- Choose the Right Database for Your Project” by Krasimir Hristozov

One of the problems for a beginner SQL programmer is choosing the right database management system to install.Most beginner students choose MySQL or PostgreSQL. But which is better? If you are facing the same problem and are interested in what you should choose, read this article. It is a great resource which can help you to decide on one of these databases.

13. “PostgreSQL count(*) made fast” by Laurenz Albe

This very interesting article is not only for SQL beginners. It helps you to understand the count(*) aggregate function and its performance. Maybe it is not an easy SQL article for beginners, but it is worth reading. The author considers where to use count(*) in PostgreSQL and when this function will be slow. This content is supported by numerous examples.

14. “Learn SQL: Primary Key” by Emil Drkusic

The PRIMARY KEY known as PK is a very important structure in databases. You need to learn about it to build database models and operate on data in tables. The author in this SQL article allows you to understand what the primary key is and how to use it. This is the overview of the primary key for both SQL beginners to learn something important about databases and for professional SQL users to refresh their knowledge. The author also explains the difference between the PK and alternative key.

15. “Using Five Types of JOIN in MySQL” by Manoj Debnath

Databases store a lot of tables which are in a relationship amongst themselves. Getting data from connected tables is a common task. This post describes five types of JOINs in the MySQL database system. Manoj Debnath starts this SQL article from the short overview of a JOIN and next explains each type of JOIN statement with numerous examples. You learn INNER JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN, FULL OUTER JOIN, and CROSS JOIN, as well as ways to operate on sets of data from tables in SQL.

16. “What is a Non-Equi Join in SQL and What is its Purpose?” by Kris Wenzel

This SQL article considers in detail a non-equi JOIN. However, despite it not being very popular, this kind of command can be useful. The author shows how to use this kind of JOIN and which problems would need it. With the help of examples presented by the author, you will better understand the non-equi JOIN. It is an interesting resource, even for those more advanced in SQL, but beginners in SQL should read it.

17. “How To Use Searched CASE Expression In SQL Server” by Vishwanath Dalvi

The CASE statement is the structure in a SQL database which returns a value as the result of an evaluation of different conditions. This article explains two types of CASE: Simple CASE and Searched CASE. The content is enriched by numerous examples of each type of CASE statement. This SQL article is worth reading for beginners to expand their SQL learning on useful statements.

18. “T-SQL Window Functions and Performance” by Kathi Kellenberger

Window functions called OVER functions, or analytics functions, are very useful, especially in computing averages, building rankings, or investigating trends across time. Therefore, it is worth expanding your knowledge on it. In this SQL article, you will find information on the main window functions in a SQL Server and how to use them. All is shown step-by-step. The author illustrates examples by using screens, which help you to understand the material in an easy way. It is helpful content for SQL beginners, especially for those who are planning a career in analytics.

19. “Row numbers with nondeterministic order” by Itzik Ben-Gan

One of the analytic functions in the SQL Server is the ROW_NUMBER(). In this SQL article, you find out how to compute the row numbers, when the order of rows in the result set matter, and when it doesn’t. The author in this post doesn't only explain the syntax of the ROW_NUMER() function in the SQL Server database system but also guides the reader through more advanced issues like UDF functions in SQL or using a subquery with the ROW_NUMER() function. The examples progress from easy to hard and allow you to learn this function in a simple way.

Summary

I have listed only the 19 best SQL articles written in 2019, but they will hopefully inspire you to learn SQL more and more. I hope that this article covering the different resources on SQL helps you to expand your SQL skills.