Now that Alejandra has built out the user-facing checkout features of her website, she’s realized that she needs to store all of this information somewhere! She needs her application to be able to store, retrieve, and modify data like usernames, shipping addresses, payment information, and more.
In order to build out these features, Alejandra needs to learn some SQL, which stands for structured query language. You might be familiar with SQL as a language that Data Analysts and Data Scientists use to query and analyze data.
SQL stores information in tables, which is simply a collection of information organized into rows and columns. If you’ve worked with a spreadsheet like Microsoft Excel or Google Sheets, you might be familiar with working with tables. To get the information, you would write a query, or a program that would retrieve data from the table.
Here’s an example of a query that would select all of the columns —the
* keyword is a shorthand for “all”— from the
SELECT * FROM page_views;
Web developers and software engineers also use SQL to build apps that can save, modify, and access data. There’s even a growing field of data engineering, which is a specialized subset of software engineers who ensure that the applications they are working with accurately and efficiently record all of the required data.
Now you try it! Add
SELECT * FROM users; to the text editor to select the entire
users table from the database.
Press run and take a look at the data that is returned. What kinds of data is Alejandra’s app able to store and retrieve? Why is it important for her to store this particular set of information?