Want to learn SQL? Start here!

Jump in to our fun, free and engaging SQL course and become a skilled data analyst faster than you can say "left join".
Turn your data into insights

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Start from scratch with the introductory lesson, or jump to the skill you want to develop by picking the lesson you want.
Lesson
1
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Introduction
Introduction: Analyzing Data with SQL
In this introductory lesson, learn what SQL is, what you can do with it, and how you can start honing your skills.
Lesson
2
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Preparation
Connecting data, tables, and creating a model
The first step in getting going with SQL is connecting your data and tables and learning the architecture for building your first model.
Lesson
3
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SELECTing
SELECTing your first data with SQL
The most basic SQL query grabs data from a table, and consists of a SELECT statement and a FROM statement.
Lesson
4
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Filtering
Introduction to filtering (WHERE)
The ‘where’ clause in SQL is a very simple way to filter out rows in your data set based on the content of it.
Lesson
5
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Filtering
Using !, =, <, > to filter data in SQL
You can use symbols like !, =, <, and > to filter data in SQL. Learn the basics of how each symbol works.
Lesson
6
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Filtering
AND / OR: Filtering your data with several conditions
Learn how to combine several conditions in your ‘where’ statement by using the statements ‘and’ & ‘or’.
Lesson
7
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Filtering
Filtering on non-exact values with LIKE
In cases where you're unable to define the conditions exactly, you can use 'like' clause to filter on values that match more or less.
Lesson
8
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Filtering
Filtering when conditions are NOT fulfilled
To filter out based on values that are not exact, you can use the 'not' statement.
Lesson
9
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Creating Columns
Introduction to columns
In this section of the tutorial, you’ll work with something new: creating new content to be included in your table.
Lesson
10
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Creating Columns
Creating a new column and naming it AS something
Apart from selecting columns from the existing data, it’s also very simple to create new columns, and name them using 'as'.
Lesson
11
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Creating Columns
Making calculations in columns
Creating your own columns in SQL becomes even more useful for business analysis when you include calculations in the columns.
Lesson
12
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Creating Columns
Using CASE WHEN as IF statements in SQL
In SQL the ‘case’ statement functions the same way as the 'if' function in Excel.
Lesson
13
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Aggregating Data
Introduction to data aggregation
This lesson introduces data aggregation. More specifically, you'll learn what to expect in this chapter and how to aggregate data.
Lesson
14
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Aggregating Data
Using COUNT, SUM, AVG, MIN, and MAX
COUNT, SUM, AVG, MIN, and MAX are the SQL functions you'll use most for aggregating data.
Lesson
15
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Aggregating Data
GROUP BY and ORDER BY
GROUP BY and ORDER BY help you summarize the results on a level in between looking at all the rows in a table and only looking at one.
Lesson
16
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Aggregating Data
Avoid failing queries with aggregate functions and GROUP BY
Learn to avoid the common causes of fails when using aggregate functions and GROUP BY.
Lesson
17
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Sub-queries
Introduction to sub-queries and CTE
Sub-queries and CTEs are ways to create temporary tables than can then be treated in a separate step in your query.
Lesson
18
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Sub-queries
SQL WITH
The SQL WITH clause is a CTE that allows you to create a temporary table which you can then treat in a separate step in your query.
Lesson
19
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JOINing
Introduction to JOIN
Introduction to the JOIN function. Learn how to increase the width of the resulting table by adding columns from other tables.
Lesson
20
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JOINing
Finding Common Identifiers & Choosing your Primary Table
Joining tables in SQL requires you to have a common identifier between tables A & B. Learn how to find it.
Lesson
21
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JOINing
Using the JOIN function to combine tables
Joining tables is a way to get data from multiple tables in your SQL query. This is great if you want to query data on separate tables.
Lesson
22
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JOINing
Combining CTEs with JOIN
Combining CTEs with JOINs allows you to have an even greater level of data to analyze, without unnecessarily overloading your query.
Lesson
23
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Conclusion
What’s next? Start analyzing your own business data
Congratulations! You've made it through our SQL tutorial. The next step is to start analyzing your own business data.
Lesson
24
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Tips & Tricks
The order of the elements in your query
In order for your SQL query to return any results, your functions should follow a specific order. Learn what that order is in this lesson.
Lesson
25
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Tips & Tricks
LIMITing the amount of data with SQL
Limiting the amount of rows your SQL query returns is a nifty way to see an excerpt of your query's results (or to see if it has no errors).
Lesson
26
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Tips & Tricks
Formatting best practices
Learn the various different ways you can format your SQL code to improve readability and understandability.
Lesson
27
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Tips & Tricks
Documenting your code
Documenting your code ensures that you and others can go back and understand what the code is doing and how it’s structured.