How to Use SQL: A Beginner's Guide

The amount of data being stored digitally is increasing at an exponential rate. As more and more information is being stored, the need for databases to store, manage, and analyze all that data effectively has also grown. Perhaps that’s why SQL (Structured Query Language), a type of database language used to manage data in relational database management systems (DBMS), has seen a resurgence in popularity over the past few years. It’s no longer just something that only computer science majors understand and use – with the rise of big data and its many related fields, SQL is a skill that anyone can learn and put to good use as a part of their future career. In this blog post, we’ll cover everything you need to know about how to use SQL as well as some common pitfalls beginners might encounter while learning it.

What is SQL?

SQL, or Structured Query Language, is the dominant language used by DBMS software to store and manage data. SQL allows you to create, read, update, and delete data in your database. Although different DBMS offer different functionality, SQL is the one language that works across all systems. Therefore, if you are switching jobs, you can use the same language. SQL is a declarative language that allows you to express what you want to happen instead of how to do it. That is, you describe the desired outcome and let the database engine figure out the best way to get there. While reading through this article, you may have also noticed terms like database and DBMS. Simply put, a database is a collection of data that is organized to be easily accessed, managed, and modified. A DBMS is the software responsible for managing databases.

SQL vs. Other Types of Database Languages

For those who are new to database languages, you might be wondering how SQL compares to other popular database languages such as NoSQL and NewSQL. Here’s a quick rundown of their differences: NoSQL – No SQL stands for “not only SQL.” As the name suggests, these database languages do not rely on SQL as their core query language. They’ve been designed to handle a different set of problems than what SQL is well-suited for. NewSQL – NewSQL refers to database management systems (DBMS) that use the core concepts of SQL, such as relational tables and SQL’s JOIN operations, but offer higher-performance alternatives to SQL.

How to Learn SQL?

If you’re new to SQL and want to learn the basics, there are a few different options you can try that you’ll find below. However, as we’ll discuss further below, not all of these methods are ideal for everyone. To start off, you can try reading through a beginner SQL tutorial, such as the one provided by SQLZoo. SQLZoo offers a variety of interactive lessons on the basics of SQL that you can complete at your own pace from the comfort of your couch. Another great way to get started is by completing an interactive SQL tutorial in an online database such as SQLBuddy or Squidex. These tools allow you to learn and practice your SQL queries without having to set up your own database, which can definitely be a barrier for beginners.

Five Steps to Learning SQL

Here are five steps to help you get started on learning SQL as quickly as possible.

Key Concepts in SQL

- Data Types: These define the type of data a column can store, such as text, numbers, or dates. - NULL: A special value used to indicate that a column doesn’t contain any data. - Data Integrity: Tells the DBMS what types of data to expect and how to react when the data doesn’t match the expected type. For example, data integrity rules can check that a phone number column always contains a valid phone number. - Primary Key: A column that uniquely identifies each row in a table.

Which DBMS Does SQL?

For the most part, SQL is used as the primary language for relational databases. Relational databases are organized into tables, with rows being individual pieces of information and columns being the various types of information that they store. SQL is used to query, or retrieve data, from these tables. Some of the most popular and widely used relational database management systems include Oracle, Microsoft SQL Server, PostgreSQL, and MySQL. Depending on your career path, you may find that you come across a particular database more than others. If you don’t work in IT, you may never have to actually use SQL to interact with a database. However, knowing the basics of how to use SQL can help you better understand the data that is being used within your organization.

Summary

SQL is the language used by all relational databases to manage data. It allows users to query data from tables, insert new data into tables, update existing data, and delete data. You can learn SQL by reading a tutorial, completing an interactive tutorial, or taking a course. There are five key concepts to understand when learning SQL: data types, NULL, data integrity, primary key, and which DBMS uses SQL. Now that you know what SQL is and how to use it, you can start putting that knowledge to good use. Whether you’re an IT professional who needs to better understand data or an aspiring data scientist who wants to dig into their data, knowing SQL is an essential skill to have.