19 Apr 2022 Dmitri Vaitkun What Are the Different SQL JOIN Types? You just can’t understate the importance of the JOIN when learning SQL. Not only is it one of the most fundamental operations in relational databases, but it is also very versatile with many different types. Although SQL JOIN may be intimidating at first, it becomes a very handy instrument in your arsenal once you understand it. Let’s explore all the SQL JOIN types! We can safely say the JOIN operation is one of the most powerful features of SQL. Read more 15 Feb 2022 Kateryna Koidan How to Keep Unmatched Rows From Two Tables in a SQL JOIN Are you looking to join two tables in SQL without removing unmatched rows? Do you want to keep unmatched rows from one or both tables? In this article, I’ll explain how to keep all the records you want by using outer JOINs, such as LEFT JOIN, RIGHT JOIN, and FULL JOIN. Examples included! The SQL JOIN is a powerful tool that helps you combine data from multiple tables of your database. Read more 27 Jan 2022 Kateryna Koidan How Do You Get Rid of Duplicates in an SQL JOIN? Do you have unwanted duplicates from your SQL JOIN query? In this article, I’ll discuss the possible reasons for getting duplicates after joining tables in SQL and show how to fix a query depending on the reason behind the duplicates. Data analysts with little experience in SQL JOINs often encounter unwanted duplicates in the result set. It’s challenging for beginners to identify the reason behind these duplicates in JOINs. Read more 13 Aug 2021 Kateryna Koidan How to Join Two Tables by Multiple Columns in SQL The SQL JOIN is an important tool for combining information from several tables. Most often, you’ll be joining tables based on a primary key from one table and a foreign key from another table. However, it is also often the case that you need to join tables by two or more columns. In this article, I’ll discuss why you would want to join tables by multiple columns and how to do this in SQL. Read more 22 Jul 2021 Kateryna Koidan What Is the Difference Between WHERE and ON in SQL JOINs? When you join tables in SQL, you may have conditions in an ON clause and in a WHERE clause. Many get confused by the difference between them. In this article, we will discuss this topic by first reminding you the purpose of the ON and WHERE clauses then by demonstrating with examples which types of conditions should be in each of these clauses. Both the ON clause and the WHERE clause can specify conditions. Read more 20 Jul 2021 Tihomir Babic How to Keep Unmatched Rows When You Join two Tables in SQL Learn how to use JOIN to keep both matched and unmatched rows when you join two tables. Joining two or more tables is a skill you need a lot if you’re working with databases. To review and practice your SQL joining skills, I recommend the interactive SQL JOINs course. It contains over 90 exercises and sections on different joining challenges. If you often join tables in SQL, you’ve probably noticed not all data from one table corresponds to data from another table all the time. Read more 9 Jun 2021 Kateryna Koidan 4 Simple Ways to Finally Learn Which JOIN to Use in a SQL Query You probably already know that you should use JOIN to combine data from several tables. But what kind of JOIN? In this article, I’ll introduce four simple ways to finally learn which JOIN to use in different scenarios. Before we jump into smart strategies for learning SQL JOINs, I suggest taking a brief overview of the major JOIN types. We’ll go through several examples to recall the difference between (INNER) JOIN, LEFT (OUTER) JOIN, RIGHT (OUTER) JOIN, and FULL (OUTER) JOIN. Read more 3 Jun 2021 Tihomir Babic Top 10 SQL JOIN Articles for Beginners Can’t find your way around the vast number of SQL JOIN articles? We’ve chosen ten JOIN articles that are worth beginning SQLers’ time. You probably know that there are many articles covering SQL JOINs. Some can be confusing because they assume pre-existing knowledge. Others are not written clearly and can leave even advanced users bewildered. The 10 SQL JOIN articles I’ve chosen are entirely the opposite. They’re written clearly and have some nice examples and visualizations. Read more 22 Apr 2021 Tihomir Babic Training SQL JOINs Doesn't Have To Be Difficult How can you train your SQL JOIN skills? And where can you do this? Also, why should you even learn SQL JOINs in the first place? All of these questions will soon be answered. One of the positive sides of the internet era is information abundance. One of the negative sides of the internet era is, well, information abundance. The amount of information and knowledge available can be overwhelming. Read more 13 Apr 2021 Zahin Rahman What FULL JOIN Is and When to Use It Learn about FULL JOIN, how to implement it, how it compares with the other types of SQL JOINs, and some of its unique use cases. Before we jump into FULL JOINs, let’s quickly recap what an SQL JOIN is. At its core, a JOIN combines data from two or more tables within a database. Tables are usually linked together using unique identifiers in each table, i.e. primary and foreign keys. Read more 13 Jan 2021 Kateryna Koidan What Is LEFT JOIN in SQL? Get to know the details of LEFT JOIN, one of the most common SQL JOIN types. SQL is mainly about getting data from databases. Very often, you’ll need data to be combined from multiple tables in your database. That’s when JOINs come into play. LEFT JOIN is one of the JOIN types that you are likely to use very often. In this article, I’ll explain the syntax of LEFT JOIN and how it works using several examples and illustrations. Read more