Acing the SQL portion of an analytics interview.

If you’ve ever been in an interview you know firsthand the feeling you get when the words “Let’s go over a few technical questions.” hit the deck.

If the above sentence makes you want to run and hide, don’t worry! We’ll have lots of resources coming your way in the next few weeks on all things interview-related.

 

Today’s topic is SQL–more generally we’ll be focusing on the topic of relational databases as they apply in the context of an entry-level/junior interview. This may apply to you whether you’re fresh out of college or you already have a year or two of experience.

If you don’t know much about relational databases and how they work, check out our article “Overview: Relational Databases and Structured Query Languages”. The article answers some basic questions about the nature of relational databases (and how to interact with them) which you should know when applying for an analytics role.

When it comes to testing database knowledge in interviews, people pretty much fall into one of three buckets.

  1. Has no idea how a database works or what the letters SQL stand for. (~80%)
  2. Has used SQL before for a class project, or outside of work for some reason. (~15%)
  3. Actually proficient in SQL. (<5%)

The percentages above are based on our own observations and shouldn’t be interpreted literally. Rather, they serve to highlight the idea that if you can move yourself from group 1 to group 2, you most likely sit within the top 20% of candidates interviewing for that analytics position you want so badly.

 

In many cases, for entry-level/junior positions you do not have to be a SQL wizard to pass a test in an interview.

The main reason for this is that many people at your level, even that ~15% who have used a structured query language to interact with a database before, have not had the chance to use it in a day-to-day business environment. As a result, even the ones who have used SQL before, are probably not that good at it.

“@analysthour, if you have to use relational databases on a daily basis to actually git gud, then how am I ever going to get good enough to get a job in analytics?”

This is a really good question, and the answer may be different from what you expect:

At an entry level, database knowledge, or lack thereof is not necessarily a deal-breaker. The reason for this is twofold:

First, in many cases people have put “SQL” on their resume because someone told them to. The SQL technical question is usually a relatively straightforward test to see if the person was telling the truth about their capabilities or if they were misrepresenting themselves–this brings me to my first point which is:

IF YOU DO NOT KNOW ANYTHING ABOUT SQL, DO NOT PUT IT ON YOUR RESUME! 

If you do the above, you are literally asking to get wrecked in your interview.

It’s the same thing as saying you know a lot about basketball when you don’t. Eventually you’re going to get asked who had the best freethrow percentage in the NBA last season. When you respond “uhhh Michael Jordan?”, the person who asked you the question is going to know you’re full of sh*t.

Second, there are a whole variety of databases available for use from companies like IBM, Amazon, etc. and they all have different versions of a structured query language that they use to query those databases.

As a result of the diversity available in the marketplace, different companies use different tools and have different best practices when it comes to handling data. SQL is not one thing–rather there are many different versions of SQLs.

Many firms would rather train most junior and entry-level employees in their own personal brand of data analysis, rather than try and break the bad habits of someone who already (maybe) knows what they’re doing.

 

This brings me to the purpose of this article–to tell you that when applying for an entry-level analytics role, your goal in an interview should not be to prove that you’re proficient in SQL.

Instead, your goal should be to:

  1. Admit that your knowledge of SQL is limited.
  2. Prove that you understand why databases are important for analytics in general, and why they’re important for your prospective employer.
  3. Prove that you understand how relational databases work and how they’re structured. (see the article “Relational Databases and Structured Query Languages”)
  4. Express your desire to learn the technical details related to the bigger picture (i.e. tell them how much you really really want to learn SQL.)

You should also take the opportunity to ask questions like:

  1. What kind of business problems have you solved using data that you would have been unable to solve otherwise?
  2. What kind of database tools  do you use here at [insert firm name here]?
  3. Is the average analyst at your form responsible for synthesizing new queries or editing pre-existing queries to pull data?

If you can accomplish all of the points above, you have successfully moved yourself from group 1 to group 2, and are now sitting in the top ~20% of the applicant pool all without learning a lick of actual SQL code!

 

Before we finish up, let’s clarify a one more thing:

If you are going to put “SQL” on your resume under “Technical Skills” you must either know SQL (well), or be able to hit all of the points above in your interview including admitting that your knowledge of SQL is limited.

Although few people want to admit that they’re lacking in a certain department or skill, I’ve seen more people botch interviews by pretending on paper that they’re more qualified than they are in reality.

If you’re in an interview, it means they’re already interested in you. The best thing you can do is be honest about what you are capable of. This applies for all skills, not just SQL.

And anyway, at this stage you should be looking for a job that’s going to get you some dope new skillz, not one that expects you to have dope skillz already.

In essence, being honest about your limitations allows you to pre-select for jobs where you’re actually going to learn something. Have you ever tried teaching something to someone who thinks they already know everything? It’s a nightmare.

Showing that you’re an honest, open book who’s ready to learn makes you an ideal candidate for firms who want to pour their resources into you and build their talent from the ground up, and those are the firms you want to work for.

We hope you enjoyed this post. If you found it helpful, please feel free to leave a comment below!

 

 

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