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.
Learning more about basic database terminology is a necessary step that will help us when we start coding. Let’s go through the entire process of creating a database. Assume our database containing customer sales data has not been set up yet, ok? So, imagine you are the shop owner and you...
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...
I would imagine some of you are Excel users and still think of an Excel or Google spreadsheet when we talk about tabular data. Please, don’t do that! Data tables, databases, and Excel spreadsheets are different things! If you'd like to learn the easiest way to set up a database in SQL,...
In this lesson, we will see how SQL subqueries can be incorporated within queries. Side note: We are going to mention the possible uses of JOINS. So, if you are not familiar with the subject, you can check out the following set of tutorials, beginning with the INNER JOIN. As their name suggests,...
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...
