SQL is used for storing and managing data in relational database management systems (RDMS) and is one of the most essential data science programming languages. A relational database is a database that organises information into one or more tables. SQL is the most universal and commonly used database language.
What is SQL?
Structured Query Language (SQL) is a standard language for storing, manipulating and retrieving data in databases. SQL is used for storing and managing data in relational database management systems (RDMS).
SQL is one of the most important data science programming languages, as it’s used for performing various operations on the data stored in the databases. The SQL language is widely used today across web frameworks and database applications.
What is a Database?
A database is a structured collection of information or data that is often kept electronically in a computer system. The database is usually managed by a database management system (DBMS). Databases are the cornerstone of any software application as this is where we store all of our data.
A relational database is a database that organizes information into one or more tables. A table is a collection of data organized into rows and columns.
Why learn SQL?
SQL is the most universal and commonly used database language. SQL controls the most commonly used database engines like MySQL, SQL Server, and SQLite.
Knowing SQL gives you the freedom to explore your data, and by learning SQL, you will also learn concepts that apply to nearly every data storage system.
There are several reasons why you should learn SQL, including:
SQL and relational databases are extensively used
We live in a data-driven world and data is almost everywhere. Storing and keeping all of that data is only the first step. Managing it and being able to use it is something else. SQL is a highly valuable skill as it enables you to work with the data stored in relational databases. Basic SQL knowledge allows you to accomplish tasks that previously may have been sent to other departments
SQL is easy to learn and get started
SQL query syntax uses common English words. Therefore, even if you have no programming experience, you can understand how to use it. There are numerous online resources for learning SQL at all levels (we will look at some of them further down), and many of the entry-level courses are free.
SQL handles Big Data
Today we often see large amounts of data being generated on a daily basis. A major benefit of knowing SQL is that you can can extract and manipulate a large volume of data from databases, instead of, for example, browse the database by opening a Excel sheet one after the other
Is SQL easy to learn?
As mentioned above, generally speaking, SQL is an easy language to learn. If you understand programming and already know some other language, I would definitely say that you can learn SQL.
Why it’s easy to learn, I would say that SQL is a logical and systematic language, which is easy to understand and to write once you get the idea of tables, columns, rows, and data types. Additionally, there are some great resources (both free and paid) available online that you can use to learn in your own pace and time.
Learn SQL: Best Free Resources
Here is the link to check out the course: Learn SQL at Codecademy
Learn SQL: Best Paid Resources
Check out the skill track SQL fundamentals at Datacamp
Although it’s not free, Udemy often has flash sales where you can get the course for under $10. When completed, the course provides a certificate to indicate that you have completed the SQL training, that you can add to your resume or Linkedin profile
Here is the link if you want to check out to The Complete SQL Bootcamp at Udemy and all SQL related courses at Udemy
Read more about the course here: SQL for Data Science at Coursera
Tips if you want to learn SQL
Some general advice:
- Free resources online: Start with free resources online, they are great. In general, the online resources to learn computer programming are endless, and there’s always tutorial, or blog explanation, that can help you. Then as you progress you can look at the paid resources.
- Take action: Your time and energy should be to start – to take action – not planning and spending too much time decide which resource to use. They majority are good, just pick the one that you think seems nice and you can’t go wrong, and if that would happen, just switch
- Learn by doing. Programming is about solving problems, and the code is your toolbox to solve a problem. To learn how to use that toolbox you must practice, practice and practice, not only watching others do it. So don’t just watch videos and do quizzes, the sooner you start playing with the code, the faster you will learn the given concepts. For example, I had my own project that I used when I learned SQL. It was a database that I built with data related to football, it was a great way for me to learn SQL
- Start with fundamentals: Programming fundamentals always need to come first. The better you understand them, the easier it is to learn the more advanced concepts
SQL vs NoSQL: What’s the difference?
When you are starting to explore SQL, you will most likely see the term NoSQL. But are SQL and NoSQL the same thing? No!
As we have already got a good understanding of what SQL is, let’s have short intro to NoSQL and then see some differences between SQL and NoSQL.
NoSQL databases (“not only SQL”) are non-tabular databases and store data differently than relational tables. Some store types of NoSQL databases include column store, document store, key value store, graph store, object store, etc.
Key differences between SQL vs NoSQL:
- Relational: SQL databases are relational, NoSQL databases are non-relational
- Schema: SQL databases utilise structured query language and have a predefined schema. NoSQL databases have dynamic schemas for unstructured data
- Scalability: SQL are vertically scalable, while NoSQL are horizontally scalable
- Store types: SQL databases are table-based, while NoSQL databases are document, key-value, graph, or wide-column stores
- Aim: SQL databases are better suited for tables and multi-row actions. NoSQL is better for unstructured data like documents or JSON
What is SQL?
SQL is used for storing and managing data in relational database management systems (RDMS) and is one of the most essential data science programming languages. A relational database is a database that organises information into one or more tables.
Why is SQL important and why should I learn it?
SQL is the most universal and commonly used database language. SQL controls the most commonly used database engines like MySQL, SQL Server, and SQLite. Knowing SQL gives you the freedom to explore your data, and by learning SQL, you will also learn concepts that apply to nearly every data storage system.