SQL is the most in-demand query language in data science for creating, manipulating, and sharing data from relational database management systems. Learn everything you need to become a confident SQL user with our SQL tutorials – from installation and relational database essentials, all the way to mastering SQL keys, joins, and clauses.
In this tutorial, we will focus on databases vs spreadsheets. It is not just Excel users who will benefit from this article. Those of you who do not use Excel regularly will learn the advantages and the disadvantages of using databases or spreadsheets. If you are familiar with spreadsheets, you...
Indexes in MySQL work like the indexes you’ll find in a library. Imagine a public or a school library with an enormous number of books on multiple shelves. It could take you hours to find a specific book. Unless you are using indexes that will group books by subject and...
The functionality of the RIGHT JOIN in SQL is identical to the LEFT JOIN, with the only difference being that the direction of the operation is inverted. Side note: Make sure you have downloaded the database that we will be working with. If you haven’t, get it here. First, let’s see...
In this tutorial, we’ll provide you with several peculiarities about the joins syntax in SQL. Not just inner joins, but any type of join. In order to fully understand the code we’ve written, you might want to take a look at the previous tutorial on that subject. Moreover, you can see...
Understanding how to construct relationships between objects using SQL joins is a turning point in the journey of learning SQL. You will also see how to relate SQL tables in practice. We will be working with the “employees” database, so if you haven’t downloaded it, you can...
