Join SQL 201 - Essential SQL

Discover the Step-by-Step  Secrets of How to Quickly use Joins and Subqueries

Are you frustrated trying to learn SQL on your own?

  • With so many sites providing reference material, learning SQL is overwhelming.
  • What these sites lack is providing you with simple-to-understand "know how."
  • These sites do a good job explaining each command, but they didn’t address "why" and "how." For instance, why do I need subqueries when I can use joins?

Hi, I'm Kris. I've been working with SQL as a developer and DBA for over twenty-five years and am here to help you.

Are You Pressed for Time and can't Afford to "Spin Your Wheels" Figuring Stuff Out?

Nothing is more frustrating trying to learn something new and be presented with so many options that is overwhelming.  No doubt in your journey to learn SQL you seen many ways to solve a problem. And it can get confusing too!

Whenever I learn a new technology I want to learn the best practice and it can be really hard to know what that is.

It seems whenever I search the internet to learn something new, I find there are several ways to solve the same problem.  Both can give the same answer, but I keep thinking, “Which one is best?  Which one should I use?

What I really want is guidance. Sure I can figure stuff out for myself, and I really like to do that, but I hate running down dead ends.   Save me time and point me in the right direction , then I’m golden.

What's the Biggest SQL Stumbling Block?

I’ve been asking my students for years “What is your biggest challenge learning SQL?” I’ve found most people are comfortable learning basic SQL to query a single table, but once you add two, three, or even more tables, they are stumped!

I guess that wouldn’t be much of an issue if all our data lived in spreadsheets, but it doesn’t, data lives in many tables!​

In order to really harness the power of a database you really have to learn to combine data from many tables into a single result. This can be really intimidating.  Do you use inner or outer joins? Should they be left or right?  What about subqueries?  Can I use those?

What should I use when? Do I need a foreign key?  It's so confusing!

Knowing Joins and Subqueries Separates you from the Rest

In my experiences I've know may people who can query a database, but very few of those took the time to learn to understand joins and subqueries.  Once you do, you'll stand out from the crowd.

Know Where to Start and You've Won Half the Battle

Often I hear from those just learning SQL they wish they knew where to start. Like I mentioned before, there are so many ways to solve a query in SQL the choice can become overwhelming. So which should you learn first?

Is it better to learn about set operators or joins first? What about subqueries?

I really like to get some early wins under my belt. So when I’m learning a new topic, I like to dip my toe in the water, get a feel, and gain some confidence. I can then build on that that to tackle more complex problems. In this way, if a concept seems difficult, I can retreat to familiar territory, reorganize, and attack from a different point-of-view.

Of course, it’s easier when the battle plan is already laid out. Rather than having to feel your way through the battle wouldn’t it be better to have a map?

Many times when working on a new project and faced with learning something new, I become conflicted. I can either work the old way, and take more time, or I can learn a new technique, such as how to use a correlated sub query, that drastically cuts the time required to complete the project, but takes time in itself to learn! Ugh… decisions… should I take a chance and learn something new or just move on and plough though the project?

It really comes down to risk and reward.

It is times like these where it really makes sense for me to know where to start and have a good plan to work though the material to learn what I need to know to complete the project on time.

Standout from your Peers

Once you master joins and subqueries, you’ll become a member of an exclusive group. Most IT professionals don’t know how to write advanced SQL, yet you’ll be able to do so.  Its not so hard to do when you can...

Get pointed in the right direction

Have a map to plan your attack.

Learn best practices.

Learning SQL can be Fun if You...

  • Save time by learning best practices.
    It's frustrating not knowing where to start, or what's important to learn.  Simplify this by focusing on best practices.
  • Avoid major stumbling blocks.
    Don't let abstracts concepts or hard to grasp ideas stop you.  Have someone guide you through difficult material.  It's less stress, saves time, and builds confidence. 
  • Gain a Valuable Skill you're Proud to Learn.
    Knowing how to do joins and subqueries is pretty cool.  Not only does it open up more possible ways to solve problems, but also sets you apart from your peers.

It's Much Easier to Learn SQL when You have Help

It is so much easier when someone is guiding the way.  I’ve found that I don’t need to be in a classroom to learn, but it really helps for me to see and hear how others do this or that in SQL.  As I learn I like to see a video demonstration on how to solve a problem or use a SQL statement, the go practices and let it sink in.

Yet video potpourri isn’t my bag. I need some structure, some guidance. A plan to learn.

I want to learn fundamentals and use those wins to build confidence to tackle bigger issues.

This is how I see you learning how to combine data from multiple queries into a single result.

I have come up with a really great approach for you to succeed

Over the years I figured out what you really need to learn and to focus on to learn how to combine data.

It just isn’t about knowing the commands; you need to know how to apply them.  In fact, once you learn the commands, you’ll realize that is only half the problem! What you really need to understand is how to “read” a database.

So my approach isn’t for you to just learn the commands’ syntax; it is a holistic approach.   It is about knowing the database, the tables, the relationships, and understand when it makes sense to use a join versus a subquery or union.

This is done by learning some fundamental database design concepts, SQL commands, and working on practice problem. Of course, it doesn’t hurt to have someone to watch.

That is why we have video. :)

Discover the Step-by-Step Secrets of How to Quickly Use Joins & Subqueries

SQL 201

If you’re having troubles understanding how to use joins or subqueries, then enroll in SQL 201. I put together a really comprehensive set of online training to teach you to understand and learn relational database design, set operators, joins, and subqueries.

​The course is broken down into four modules:  Relational Database Concepts, SQL Set Operators, Joins, and Subqueries.

Each module consists of several lessons that focus on a topic.  For example, in the outer joins lesion, we introduce the topic, explain the difference between left and right outer joins, teach about full outer joins, and then show practical uses for outer joins.  This is done using several five to ten minute videos using examples you can try in the Adventure Works database.​  Below you'll see a portion of one of the lessons.

  1. Use video and test to learn new material:   Once you have listened to the video and gone through the course materials, Reinforce your learning with sample problems followed by online quizzes.
  2. Questions? Just ask! I’m here to help you. Email me if you have any question about the course material and I’ll do my best to answer it.
  3. Take your time:  Learn at your own pace and don’t stress. You have unlimited access to the course.
  4. Be on the go!  Take the course anywhere, from your computer at home, or on the go, via your smart phone.
Portion of Sample Lesson

My goal is to make learning SQL frustration free!

John Doe UI/UX Designer

“Best Regarded, Best Organized”

"My reason for wanting to use your SQL course/s, is that is appears to be the best regarded, as well as the best organized, of other SQL training.

I am an accountant, and as I have had to use SQL over the years, I have just begged and borrowed pieces of code to make things work when I needed to. I want to finally get some real instruction - thanks!"

Scott S.
- Accountant

“Great detail and clear concise explanations"

"Great detail and clear concise explanations. I've been working with SQL for only a year and I think you, out of all of the tuts and docs that I've been reading, actually explained it in a unique way that it was the easiest to comprehend.Thank you and keep them coming."

- Software Contractor
John Doe UI/UX Designer
John Doe UI/UX Designer

“Wonderful tutorial”


Again so wonderful tutorial , It is so clear and understandable before I have read a lot of articles about joins but this was completely distinct.Thank you sir for this part."

Sherdill N.

Join SQL 201 and Finally Learn Joins and Subqueries!

Get started today!  Finally figure out how joins and subqueries work.  Join SQL 201 today and learn to combine results from multiple queries into a single result.  I'll teach you using simple to understand English and awesome online videos.

Pre enroll today to save your seat.  Spots are limited.  There is no obligation to join.

A Few More Testimonials to Prove it Works for Real People

John Doe UI/UX Designer

“If I could send you cookies I would!”

“Your site has been extremely helpful, and I just want to say thank you for putting this resource together. I have been using SQL for a few years now, but here and there I come across hurdles and this site has found to be helpful to understanding what I may be doing wrong.

Thanks again for all of your help, it is greatly appreciated!P.s. If I could send cookies I would!  :)


“Always refreshing...”

“It is always very refreshing to read well written articles and take your classes on on hard-to-grasp technical topics. Great job.”

Klaus N.
- Aspiring DBA
John Doe UI/UX Designer
John Doe UI/UX Designer

“Teaching in a clear and progressive way...”

“Really appreciate your way of teaching important sql concepts in such a clear and progressive way. I had the impression to find only either basic resources or very advanced ones.”

Frédéric V.

Kris Wenzel
Creator of SQL 201

About the Author

Hello my name is Kris.  I’m here because I am passionate about helping non-techie people to overcome their fear of learning SQL.

I know what it is like to not know where to start or whether the time spent learning is worth the effort.   That is why I am here to help you to get started in an easy to follow step-by-step manner.

Let's put my twenty seven years of experience with databases to work for you!

Why pay for a class where there are so many free resources on the web?

I agree there are many great resources on the web. Like you I use them all the time! In fact, I’m always referring to them to help me make my courses better; however, the value you get from this course doesn’t come from information you can get elsewhere.

Let’s face it, tons of sites write articles about joins and subqueries.

No, the true value comes from how I explain the topics to you and my commitment to helping you learn and understand it.

I’m known for having a really good knack for breaking down complex ideas into simple steps. Also, I’m truly here to help you. If you send me an email with a question about any topic we cover on the course, I’ll answer it. This is something you just won’t get from the free resources on the web.

Plus, think of learning like cooking. If you want to make a complicated dish, it should be simple: pick a recipe, purchase the ingredients, and cook! It doesn’t work that way though does it? There is more to cooking than just following instructions.

And like cooking, there is more to learning SQL than just following the instructions.

Through my online course I’ll really dig into the what and whys of joins and subqueries to help you really understand how to combine data from multiple queries into a single result.

I don't have enought time to take a course

I get it, between family, kid’s sports, and work, it does seem there isn’t any time left in the day, but there is.

You see, were not looking for large blocks of time to study and learn. If you needed to commit to a hours every other night I would agree, but you don’t need that much time. In fact, I would say that you can start taking this class in ten to twenty minute intervals.

The course is designed in several ways to help you out:

First each video lesson isn’t long. You find most are between five to ten minutes long. Each lesson focuses on a single topic. If you make your goal to start to learn a topic, and then after a couple of sessions, learn it, then you just made progress!

Second, you can use your smartphone to take the course. Each lesson is adaptable to smart phones and tablet size screens. This means you can take the course on the go and nor do you need a complicated setup to do so.

Last, the course keeps track of your progress, so you’ll know what lessons you’ve completed. This makes it really easy to pick up where you left off.

See, whether you commute to work on the train, sit wait for your kids at soccer practice, or have a spare thirty minutes after the kids go to sleep, we make it really easy for you to learn joins and subqueries.

What is the Advantage of Enrolling in SQL 201?

There are many advantages to taking SQL 201. One of the biggest reasons is to save time! And from what I have heard from you time is something we all don’t have, so why waste it?


  • Ask a question about the course and I'll answer it.
  • Build confidence with small wins so you can learn more.
  • Reinforce learning using video, written summaries, sample problems, and quizzes.
  • Learn more through simple to understand English.
  • Based on examples you can follow in Adventure Works 2012.


  • It takes longer to learn.
  • Learning material out of order is harder and discouraging.
  • With no one to help, it is harder to find answers to your questions.
  • There are many ways to combine data, but how do you know you’re learning the best practice?
  • Difficult to find sample problems and quizzes to reinforce what you have learned.

Here's  What You Get  When you Join in SQL 201

  • Unlimited access to course material
  • Video tutorials clearly explaining important concepts.
  • Quizzes covering lessons learned.
  • Four course modules on join, subqueries, and more!
  • One-on-one email support.  I'll answer any question you have about the course material.
  • Video downloads
  • Lesson reviews that summarize important concepts.
  • Sample problems with detailed answers

100% Satisfaction Guaranteed


100% Satisfaction Guarantee

I personally guarantee if you make a diligent effort to use just a few of the techniques in this course, you'll be able to combine data from multiple tables into a single result.

At any time during the next 30 days, if you sincerely feel I fell short in any way on delivering everything I promised, I'll be happy to give you a complete refund. Even if it's on the last day.

Frequently Asked Questions

What Modules are Covered in the Course?

Is there email support?

What DB is used to teach the course?

What topics are covered?

Why did you create SQL 201?

Who should take this course?

P.S.:: While the price on this course will probably always be low, it's unlikely to remain THIS LOW forever.

There are strict limits to how many people I can take at any given time. So if you click the order button and all you see is an opt-in form, it means we're unfortunately overbooked and you'll need to be placed on a waiting list. Therefore, if you're at all interested please get in TODAY!

Yes, I want to start learning join and subqueries now!