For an instructor lead, in-depth look at learning SQL click below.
Welcome to the world of SQL, or as it is more commonly known, Structured Query Language. SQL is a powerful tool used for managing and manipulating relational databases. It’s used by big tech giants like Google, Facebook, and Twitter to make sense of their vast amounts of data. But don’t let that intimidate you, let’s start right at the very basics.
What is SQL?
SQL (pronounced ‘sequel’) stands for Structured Query Language and it’s used to communicate with databases. It is a standard language for managing and manipulating databases, allowing you to query, update, and reorganize data, as well as create and modify the schema of a database.
Writing your first SQL Query
Normally, a SQL query is performed on a database with existing tables. But to understand the basics, let’s write a very simple SQL query together.
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SELECT * FROM Users |
This is a ‘SELECT’ statement. The asterisk (*) symbol is a wildcard that means “everything”, it refers to all columns in a table. Thus, this query retrieves and returns all the data from the ‘Users’ table.
Refining your SQL Query
Well, retrieving all data from a table might not be something you’d always want. What if you only wanted to get the names of the users and not all the other information? SQL allows you to do this too.
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SELECT name FROM Users |
This refined ‘SELECT’ statement will only return the names from all the entries in the ‘Users’ table.
Manipulating Data
SQL is not only about getting data; it includes modifying it too. Let’s look at how you would update a user’s detail:
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UPDATE Users SET email = <a href="mailto:'newemail@mail.com'" >'newemail@mail.com'</a> WHERE name = 'John' |
This ‘UPDATE’ statement will change the email of the user whose name is ‘John’ to ‘newemail@mail.com’.
Through this tutorial, I hope you have gotten a basic understanding of what SQL is, and made the first steps of your journey into the world of SQL less daunting. We have a long way to go with many more exciting things to learn!
Final thoughts
Learning SQL is like learning any new language – it takes time and practice. The key is to keep working through examples and gradually introduce more complex concepts. Happy coding!