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How Much SQL Do I Need to Know?

Learning a new skill or starting a new profession can be a real challenge, especially when you’re unsure of how much you really need to know before taking the plunge. Imposter syndrome is also a real thing – how could you possibly catch up with all those SQL ‘experts’ who seem like they’ve been doing this since they were in diapers? The good news is you can learn SQL quickly and easily, and you don’t need to know nearly as much as you think you do.

So how much SQL do you really need to know?

Well, let me ask you this: How long is a piece of string?

Some pieces of string can certainly be quite long. Like this beast of a ball of twine from Darwin, Minnesota.

twine ball

Source: Hjblogs

It’s 12 feet in diameter and weighs more than 17,000 pounds. The man who made it spent four hours a day over TWENTY-NINE YEARS carefully creating it.

Weird Al Yankovic even wrote a song about it.

twine ball

What’s my point?

Well, this piece of string is clearly at the upper end of string sizes.

It’s a bigg’un.

It’s award-winning.

It took decades to achieve.

But if you want to get into string ball creation yourself – you certainly don’t have to reach the same size of twine before you can add it to your resume. In other words, you don’t have to be the master to get involved.

The same goes when you learn SQL.

A Little SQL Means a Lot

You absolutely do NOT need to be an SQL expert to work in the field. In some professions the opposite is true and you need to reach great levels of knowledge before building a career in that industry. You want your brain surgeon, for example, to know as much as humanly possible about brains. You want your airline pilot to be pretty blimmin’ confident about which buttons she’s pushing.

The same doesn’t go for learning SQL – and that’s great news for the thousands of SQL students out there who want to start using this amazing language for all manner of professional and personal pursuits. With SQL, a little really can mean a lot. You could take this SQL Basics course now, for example, and then walk straight into a simple SQL analysis project with a whole arsenal of new skills at your disposal.

This isn’t a white lie, it’s not an exaggeration. SQL can be useful to you in even small doses.

But Why SQL Over Excel?

People often ask me “if I don’t need to know much SQL, why do I need to know any at all?”

Often those who are simply interested in SQL for side projects or as a boost to their existing job, will ask if it’s not just easier for them to hone their Excel skills rather than starting from scratch with SQL.

My answer?


Here’s the thing about Excel. It takes MINUTES to do in SQL what Excel can take an hour to achieve. Most of us don’t have the luxury of fluffing around with an Excel table for hours every day, only to achieve what SQL could have done in a fraction of the time.

SQL also comes out on top because it separates your analysis from the data itself. If you are working on a project with colleagues and want to share your workings with them, you can send small plain text files with your SQL queries so that they can run the same SQL analysis themselves.

Lastly, when you work with Excel files you run a huge – nay, GINORMOUS, risk of making accidental changes to data, of encountering version control dilemmas, and of triggering cumbersome computer slowdowns when large Excel spreadsheets start spinning that little wheel of doom.

Stay away from Excel, kids. SQL wins the day here.

The SQL Basics

If you’re wondering how much SQL you need to know, getting a taste for the basics is a great way to give a little context to your question.

If I tell you “you need a foundational knowledge of SQL to use it in a professional capacity," you might feel a little overwhelmed at the prospect. But learning the SQL basics is a lot easier than you might think. Let’s take a look at the main things you’ll learn as an SQL beginner and what that knowledge will allow you to do in the “real” world.

First things first, know this: SQL is one of the easiest languages you can learn. It’s rooted in intuitive English syntax – meaning less gobbledegook and more ease of use.

If you can learn how to SELECT, INSERT, UPDATE, and DELETE in SQL – you’ll be around 70% of your way towards SQL proficiency! That’s not bad for one course worth of learning!

Let’s take a look at the SELECT query as an example of just how easy SQL is to learn.

Here’s a table showing a list of pupils enrolled at a school. Let’s call it STUDENTS.


To use SELECT, all you would need to write is this:

SELECT * FROM Students

This is asking the database to selection all columns (* means “all columns”). Great to know, but not yet very specific.

So what if we wanted to know which students had attendance records of 215 days per year and under?

To do that, we’d need to use the WHERE clause, which specifies what data we want to identify. Our query would look like this:

SELECT * FROM Students
WHERE Attendance = <215

Once you’ve nailed the SELECT and WHERE statements, you can build on your knowledge by learning INSERT, UPDATE, and DELETE.

INSERT is the query you’ll use to add rows to a table, and looks like this:

INSERT INTO tableName (column1, column2, …)
VALUES (value1, value2, …)

UPDATE helps you to change column values, and is written like this:

UPDATE tableName
SET column1=value1, column2=value2,...
WHERE filterColumn=filterValue

And DELETE does what it says on the tin: removes rows from your table.

DELETE tableName
WHERE  filterColumn=filterValue;

If you’re starting to get a taste for just how simple SQL might be to learn but want some better explanations and a few exercises to cement your new learnings, check out our SQL Basics course – it’s designed for absolute SQL beginners and will teach you everything you know to start using SQL in earnest.

The thing about SQL is, different roles require different levels of knowledge. So asking “how much SQL do I need to know” really needs that handy WHERE clause.

How much SQL do you need to know…

WHERE Your Job is in Business?

What if you’re a businessperson or entrepreneur looking to make use of SQL in your work? How much SQL do you really need to know?

If you’re wanting to learn some SQL skills in order to better analyze your revenue and profits, then don’t fear – you don’t have to be a super technical person to make use of some basic SQL syntax.

SQL is all about extracting useful information from your databases. That’s why we created this Revenue Trend Analysis course, to help people like you better understand your business trends. Let’s say, as a business owner, you want to know which products your business sold in Q2 that cost less than $10. Perhaps you want to find out if these low-cost items are selling well enough to be worth your time and effort.

The SELECT query is your first port of call. You want to select the relevant fields from your database so that you can start to analyze the information. Your query would look like this:

SELECT Product_Number,

SELECT? Nailed it.


The next basic query you’ll need to know is the FROM clause. This helps you define where you want to take the information from – in other words, from which table in your database. In this case we want to take them from our product inventory, so we’ll write our query like this:

SELECT Product_Number,
FROM   prod_inventory;

FROM? You’re already killin’ it.


Once you’ve specified where you want to take the data from, you’ll move on to the WHERE clause. WHERE is all about refining your query so that only the information you really want to know is returned to you. In this example, we want to see the products in our inventory that cost less than 10 dollars.

To do that, we’d run the following query:

SELECT Product_Number,
FROM   Cust_Products 
WHERE  Unit_Price < 10;

WHERE? You’re a WHERE Rockstar now.


Ok! So things are going great. We’ll have returned a list of our products that cost under $10. But what if we have more criteria? That’s where the AND clause comes in. If you want to see products that cost less than $10 but more than $5, AND can help you like so:

SELECT Product_Number,
FROM   Cust_Products 
WHERE  Unit_Price < 10 and Unit_Price > 5;

AND? You’ve got a PhD in AND now, friend.


When you are wanting to analyze information, the way it is sorted makes a big difference. ORDER BY is an extremely helpful clause that lets you organize your results exactly how you need them. Let’s say you want to order the results alphabetically by product name. You’d add this to the end of your query:

SELECT Product_Number,
FROM   Cust_Products 
WHERE  Unit_Price < 10 and Unit_Price > 5;

ORDER BY Product_Name;

ORDER BY? Order by how awesome you are at SQL already!


So that’s a business example for using SQL.

But how much SQL might you need to know…

WHERE Your Job is in Marketing?

Marketers of the past focused more on words and perceptions to target audiences and sell products and ideas. These days, perceptions no longer cut the mustard. Companies big and small demand their marketing teams are savvy analysts who can take company data and formulate marketing strategies that are founded in facts and truly get results.

To truly know who you customers are, their likes and dislikes, the shopping habits, and their interaction with your marketing campaigns, you really need to get your SQL analysis hat on – pronto.

In the past, marketers worked with their IT colleagues to get these data-based answers to audience-related questions. These days, data analysts and other members of the IT team are so busy, you’ll often be asked to wait two weeks for a gap in their schedule.

Why wait when you can perform these simple queries yourself?

To use SQL in your marketing career, you don’t need ten years of experience, a Masters degree, and years of upskilling. The likelihood is you can use SQL in your marketing activities with just the SQL basics and a few tutorials in creating database structures.

Add to the SELECT, WHERE, and ORDER BY fundamentals with a solid understanding of GROUP BY and JOIN – and you’ll be well on your way to striking marketing gold with your command over databases.

With Marketing and Business needs covered, let’s take a look at the other end of the SQL knowledge scale.

How much SQL do you need …

WHERE Your Job is in Data Engineering?

Things are a little different if you’re looking to go from SQL grasshopper to SQL Master. If you’re planning a career in data engineering or data analysis, then knowing a lot about SQL is actually going to be important.

There’s no hard and fast rule about how much SQL a Data Engineer will need to know, but let’s put it this way – you’d want to have mastered more than the SQL basics to feel confident in such a role.

Data engineers are often also proficient in other programming languages, increasing the number years it will take them to reach expert status.

Luckily LearnSQL has you covered even if you’re aiming for the highest echelons of SQL expertise. Our Advanced SQL Learning Track covers window functions, complex reports, and recursive SQL queries, among many other things. What's more, our platform offers many different ways to practice advanced SQL online.

One Small Step For SQL Student …

There are lots of things you need to know a lot about to do well at. Surgical anesthesia. Boat building. Making macarons. SQL is not one of these things. With SQL, a little can go a looong way, just like butter, car oil, or time spent with your cranky Aunt Mildred.

If you want to become a true SQL expert, you may well need to spend many years honing your craft. But expertise is for those wanting to reach high levels of seniority as a data engineer or analyst. If you’re a marketer or a businessperson and you’re looking to use some SQL in your day-to-day work, then you won’t need to learn anywhere near that much. SQL is everywhere. So, what are you waiting for?