Learn SQL in an Interview with Dennis Still

Big Data Chronogram

I recently got to know Dennis through twitter and essentaiSQL.com.  If you’re non-technical, you’ll find this interview inspiring.  You too can learn SQL.  If you’re a techie or IT pro, Dennis provides great comments and insights on SQL and data services; ways to better serve your customers.

Before we begin, I want to remind you all that if you have other questions you want answered, then post a comment or tweet me.  I’m here to help you.

With that let’s begin the interview!

1.  When you first learned SQL, what were some of the frustrations you had and what would you recommend to today’s beginners to avoid them?

I came to SQL through a non-tech, non-IT world.  I had spent a good deal of time in graduate school studying political science.  I was focused on American Politics, particularly Congress, but legislative actions/processes.  Because of that, I had a secondary field of Quantitative Analysis.  American Politics is all about understanding processes through data analysis.  I learned what STATA, SAS, and SPSS were from that experience.  I had crunched large data sets and analyses through those tools…and of course the Microsoft Suite of Excel and Access.

political-science-dataWhen I decided to leave academia, I started teaching Social Studies at the high school level.  I was leveraging my government graduate program studies…to help students understand government better.  After a few years of that, I was interested in exploring some other opportunities and a chance to join Thomson Reuters happened.  Here, I began to use Business Objects and Access fully to leverage larger and larger data sets, all with a goal of understanding customer usage and how it impacted our department and the overall business.

When I started using Business Objects, I realized that I needed to get some training in SQL.  I had a ton of experience and training in data analysis, but the technical side of pulling/extracting/manipulating raw data was a bit underdeveloped.  So, took some courses.

The biggest frustration I had with training in SQL was the bias of the instructor.  The one I had was focused on Oracle’s products.  We learned SQL via that perspective.  They are not the same.  Each has its own quirks.  My suggestion would be to make sure you get training across different DBMS.

Secondly, go to some of the free resources, like Kris’ blog/website or other less expensive options like Lynda.com.  Take some online things first, get a feel for it.  There are lots of courses that cost thousands of dollars.  Make sure you need it before going to your boss and asking for money to do so.

2.  Why did you start using SQL and why continue throughout your career as a data scientist / data hacker?

I started using SQL mostly out of self-preservation and reliance on others.  I ran into roadblocks sometimes from an IT perspective when asking or pushing for more and more data access.  The way some organizations are structured, it was odd having someone on the business side start asking probing questions about why certain dates were wrong, or numbers weren’t adding up or lining up with expectations.  In almost every job I have had as a data scientist / data hacker, I have found places were because of the technological approach, the user experience was suffering due to inaccuracies in how data was rolled up or collected.

Using SQL became a way for me to get what I needed ASAP.  No longer did I need to wait for IT support to send me a set of data.  I could go and get what I needed, when I needed, and how I wanted it done.  It becomes a powerful tool to extract backend, “our data”, and tie that to things like Google Analytics, or Zendesk, Facebook Insights, Twitter, or Pinterest data sources.  I can now get an almost 360 degree view of the customer experience or marketing funnel.

SQL gives me the ability to have greater insights and understanding of the entire data landscape for the business I am working for.  Right now, I get the chance to look at things related to when I work and the almost 6,000 customers who use our app to schedule hourly employees.  Taking that data and applying to our backend data via SQL is incredibly powerful for the business to understand and leverage.  We can make better, stronger, and faster decisions about which way to go for more business and stronger growth.

3.  What DBMS do you use, have used, and why do you like it?

I am currently using Sequel Pro for the Mac.  I like it a lot, very functional and gives me the ability to quickly create queries and save things efficiently.  I have used other tools like MySQL and SQL Server.  I also have used Access and Business Objects functionality from the SQL side as well.  The reality is that once you get the hang of one DBMS, you can pretty much work with in any other.

I am not a database administrator, I don’t spend every day in SQL.  However, the functionality I need as an intermediate to advanced SQL user can be found in most DBMS.  The cool thing is that I also get a chance to use a product called Chartio, which is a data visualization type tool similar to Tableau, but is much more SQL based.  I actually can create in a couple of different modes via this tool.  I often write my SQL queries in Sequel Pro and then copy/paste into Chartio.

4.  Why should someone study and use SQL?

The reality is that you can get away being a data analyst and/or business analyst by simply using Excel, maybe some Access, and be done.  However, SQL gives you so much more ability to get to data that is much more valuable to a particular business or organization.  SQL is a tool that gives you the vision you need into the raw data.

I like being self-reliant, so that is why I use SQL.  I don’t have to rely on DBA or IT techs to get data and send it to me.  I can experiment with the query to get exactly the data I am looking for.  I can segment on my own via SQL, filter things out, deal with “null” values, and just data explore much better with SQL.

It isn’t as hard as some folks believe.  You will become a better data analyst, advisor, and hacker with this knowledge.


Dennis’ Biography

Dennis Still SQL AnalystDennis Still is the Lead Business Analyst & Data Hacker at When I Work, the easiest way to schedule, communicate, and track attendance with hourly employees. Dennis loves helping people figure out tough business questions through the use of data analysis. He is passionate about evangelizing how awesome data analysis, data science, insights analysis, or data hacking is and you will find him often presenting at conferences, talking/teaching students, tweeting, and blogging. He is all about helping customers succeed in understanding how their data can help their businesses.  Feel free to reach him via @denstill on Twitter.

Kris Wenzel

Kris Wenzel has been working with databases over the past 28 years as a developer, analyst, and DBA. He has a BSE in Computer Engineering from the University of Michigan and an MBA from the University of Notre Dame. Kris has written hundreds of blog articles and many online courses. He is loves helping others learn SQL.

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