Puzzles Archives

Solving puzzles is a great way to learn SQL.  Nothing beats practicing what you’ve learned.

Once you have figured out the puzzle, post your answer in the comments so we all can learn from one another.

We also discuss puzzle and more in Essential SQL Learning Group on Facebook.  Be sure to find us there!

Here are two of my favorite puzzles you should try to solve:

All the examples for this lesson are based on Microsoft SQL Server Management Studio and the sample databases AdventureWorks and WideWorldImporters.

You can get started using these free tools using my guide Getting Started Using SQL Server

Joins versus Subqueries SQL Puzzle

Joins versus Subqueries

In this puzzle, we’re going to learn about joins versus subqueries.  In many queries you can substitute joins and subqueries.  Yet, since each has their strengths, it isn’t wise to do so.  Once you have worked through this puzzle you see some of the benefits and disadvantages of joins versus subqueries. Solving puzzles is a […]

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What is the difference between a subquery and inner join?

In this puzzle, we’re going to learn how to rewrite a subquery using inner joins.  Knowing about a subquery versus inner join can help you with interview questions and performance issues.  Though subqueries have unique abilities, there are times when it is better to use other SQL constructs such as joins. By reading this article […]

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Learn how to Calculate the Median Value using PERCENTILE_DISC

In this puzzle we’re going to learn how to find the person whose birthday, among others, is in the middle.  Knowing how to calculate the median value is a good skill to have.  As you start to explore business intelligence you’ll come across similar problems to solve. Also, be sure to check out the bonus […]

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Learn to use the Data Dictionary in SQL Server

In this puzzle, we’re going to learn how to query the data dictionary using SQL Server.  Knowing how to query the data dictionary is good to know.  There are many questions you can answer about your database through the data dictionary. For instance, do you know how many of your table don’t have a primary […]

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Learn how to Work Joins and Messy Data

In this puzzle, we’re going to learn how to join dirty data using SQL Server.  Many times you’re forced to use someone else’s data.  Since it is their system and data, not yours, you can’t always fix the inconsistently formatted data before it is in the database. So how can you use it?  Do this […]

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Work with the AdventureWorks Bill of Materials using Subqueries

In this puzzle, we’re going to learn how to work with the AdventureWorks Bill of Materials table.  Companies use a BOM (Bill of Materials) to itemize the products that are used or contained in another product. Solving puzzles is a great way to learn SQL.  Nothing beats practicing what you’ve learned.  Once you have figured […]

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SQL Puzzle:  How to Calculate Moving Averages

In this puzzle, we’re going to learn how to calculate moving averages by working through a hypothetical stock market example. Solving puzzles is a great way to learn SQL.  Nothing beats practicing what you’ve learned.  Once you have figured out the puzzle, post you answer in the comments so we all can learn from one […]

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Rank Data with SQL

In this puzzle, we’re going to work through a problem to identify the top and bottom 25 percent to rank student scores. Solving puzzles is a great way to learn SQL.  Nothing beats practicing what you’ve learned. SQL Puzzle Question In today’s puzzle assume you’ve been asked by the head of the Mathematics department to […]

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