MySQL Database Developer

Database Management

About this test

MySQL Database Developer Online Test: How it is structured and how it can help you hire your best candidate

Using our MySQL Database Developer online assessment test will assure your candidates’ skills in all aspects of development for MySQL using 24 highly detailed questions.

All questions represent practical, general knowledge around developing for MySQL and should be known by strong MySQL database developers.

The test is put together by the world-renowned team. They’ve authored more than 65 in-depth Pluralsight courses on RDBMS topics, and have been providing high quality DBA and developer training and consulting since 1995. They are intimately familiar with all aspects of the chapters in this test and also have extensive experience interviewing Database Developer candidates for their clients.

The sub-chapters were picked after considering the broad scope of developing for MySQL, and the SQLskills team has assessed the six most vital areas to evaluate the qualifications and practical experience of a specific candidate. See all chapters to the right.

By using our MySQL Database Developer online assessment test, recruiting talented developers will be easier. You will have a significantly higher chance of employing a strong candidate, as well as eliminating the risk of hiring an under-qualified candidate who lacks real-world experience.

How would you use this test?

This online assessment test has a number of use cases:

  • Evaluate MySQL developers on their understanding of MySQL development fundamentals
  • Filter out candidates for your work based on their ability to understand complex scenarios
  • Make sure that candidates have real-world, practical knowledge of developing for MySQL, instead of just book knowledge or having taken a development ‘boot camp’

Which areas (chapters) will be covered in the test, and why was it chosen that way?

Normalization and Constraints

An important development skill when designing a database is applying relational theory to construct a data model for the data being stored. This means a strong candidate will understand how to normalize the data so it can be efficiently stored and searched, plus how to codify the relationships between fields in different tables using appropriate constraints.

Schema Design

A strong developer will be able to construct a schema that accurately and efficiently represents the data model. This means choosing appropriate data types, table design, functions and procedures that don’t hinder performance, and even temporary tables used during query execution.

Indexing Strategy

One of the most important tasks of a developer is choosing the index strategy for each table, taking into account the various data types and the queries that will be performed on the table. A strong candidate will also know how to choose an appropriate primary key, avoiding common performance pitfalls and behavior misconceptions, use covering indexes, and how and when to consolidate similar secondary indexes.

Data Modification

There are many things to consider when inserting, updating, or deleting data, including how to avoid excessive blocking, how to load data, when to use explicit transactions, when to change isolation level from the default, and how the various defaults work. A strong database developer candidate will be aware of the problems that can occur when modifying data and how to avoid them.

Querying Data

Probably the single most important thing a MySQL database developer does is write effective queries to select data from the database. It is therefore important that a strong candidate knows how to write a wide variety of queries, including creating cross-table selects using joins/subqueries, using aggregates, using windowing functions, dealing with NULL data, and writing search arguments to ensure indexes can be used appropriately.

Query Plan Analysis

Of course, when writing queries, a great database developer will check to make sure that the query plan that MySQL has generated is efficient. This means a strong candidate has to be familiar with query plan analysis using EXPLAIN, which includes understanding operators (their meaning and associated costs), making sure aggregates are correct, and ensuring that the most efficient access to the data is being performed, using the appropriate indexes.





Maximum completion time

39 minutes

Chapter(s) 6
  • Query Plan Analysis
  • Querying Data
  • Data Modification
  • Indexing Strategy
  • Schema Design
  • Normalization and Constraints
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Most recent MySQL Database Developer score
MySQL Database Developer
Query Plan Analysis
Querying Data
Data Modification
Indexing Strategy
Schema Design
Normalization and Constraints
Try a sample question from our MySQL Database Developer specialist
A Database Developer is tasked with creating a new customer database. They are told that there should be a separate table for each set of related data and that each column should be atomic with no repeating groups. Any non-key attribute should be fully functional dependent on the primary key, and no non key attribute is transitively dependent on the primary key. What normal form does this requirement meet?

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Made by one of the leading experts

I’ve been heavily involved with Microsoft SQL Server since I joined the development team at Microsoft in 1999, and I know the importance of bringing in promising job candidates. That’s why I jumped at the chance to help Kandio help companies find real SQL Server experts.

Paul S. Randal

Paul S. Randal

CEO and Owner, SQLskills
SQL patent holder, Microsoft MVP
Co-author of all our SQL related tests

Paul S. Randal

I’m Paul S. Randal, and I’m one of Kandio’s go-to guys on everything SQL Server.

After working on SQL Server itself for almost nine years, I joined my wife running a world-class SQL Server training and consulting business, so I know what qualities make a great SQL Server developer or DBA. With 15 thousand twitter followers, and having recorded or produced more than 65 Pluralsight courses on SQL Server, people trust my knowledge and opinions.

I wrote and taught Microsoft’s prestigious Microsoft Certified Master qualification, as well as the course assessments and practical exam, so I also know how to write questions that really evaluate a candidate’s real-world knowledge. Using the assessments I’ve written for Kandio, your business can find your next SQL Server expert.

My Experience

I’m an author, consultant, and top-rated speaker having spoken at PASS, TechEd, SQLintersection, and numerous other events around the world. I spent 9 years working on the SQL Server team, ultimately responsible for the entire Storage Engine. I left Microsoft in 2007 to co-own and run, and I’ve been a SQL Server/Data Platform MVP ever since. I’ve written numerous whitepapers for Microsoft, articles for SQL Server sites, and more than 1,000 blog posts about SQL Server topics. I know SQL Server inside and out!

  • September 2007 - Present
    CEO and Owner
  • 2012 - Present
    Author and course producer for my team
  • January 1999 - August 2007
    Microsoft (SQL Server team)
    Developer, Principal Development Lead, Principal Group Program Manager

My Achievements

I’m a prolific creator of SQL Server educational content and have a passion for helping people learn about SQL Server. I’m also a renowned expert in SQL Server data recovery and SQL Server internals.

  • Over the years
    Multiple #1 rated conference sessions and workshops at Microsoft TechEd and PASS Summit
  • Over the years
    Two software patents for SQL Server technology
  • Over the years
  • 2008 and onward
    SQL Server/Data Platform MVP since April 2008
  • 2012 and onward
    Started recording for Pluralsight. More than 65 SQL Server courses recorded or produced.
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94% of all questions our support receives, can be answered in the below FAQ

I have many candidates - will they all receive the same questions for equal assessment?
Short answer:

Yes, all candidates are equally assessed, when you use Kandio.

Long answer:

All our tests have different questions that might or might not change from vacancy to vacancy.

However, once you lock a recruitment round in, the questions will lock in as well for all candidates going through your assessment, so that they are equally screened.
How can the exam score help me to make a better hiring decision?
Overall it would be best if you kept in mind that Kandio offers help with assessing your total pool of candidates. The point with this plan-of-attack is to give you a tool that will enable you to pinpoint the very underqualified candidates quickly, and promptly discard of them. As well as locating the strong candidates, and invite them for an interview before your competitor does.

The difficulty of our tests is serious in general and is meant to find the lesser qualified. So you shouldn’t disqualify a candidate at 67%, just because you have someone who’s testing 70%. Or even 85%.

Kandio is a tool you should use in addition to other means such as:

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The reason we have priced Kandio the way we have is that it’s meant to be used alongside other decision factors, and not as a sole dictation of which candidate to employ.
Why Kandio over other tests? And why not a free-writing test?
All Kandio assessments have a difficult multiple-choice approach and a very clear and tangible scorecard at the end. We only work with objective measurements and completely disregard candidate values such as consistency in work, ability to teamwork, humanity, and care for colleagues, sociality, and the likes.

The reason for this is that in today's tech-oriented world, we often see a significant amount of different solutions to the same problem. If we offered free-write assignments, candidates would need to be assessed one by one, which obviously would be impossible at our price point.

With us, you're buying access to a robust set of exams, written by the world's best authorities, with well-functioning scorecards to make recruitment easier. And on top of that, we are using big-data to benchmark all your candidates across other similar candidates.
How difficult are the tests Kandio offers my candidates?
All our tests are authored with serious difficulty in mind. We accept only the best test authors onto our platform, and a fixed percentage of revenue goes directly to our authors to keep content updated, and authors happy.

Our goal is to weed out the least competent candidates in the most common knowledge within your desired field.

Because of this, you should keep in mind to adjust your salary expectations and level of acceptance, if you’re looking for junior roles, mid-level roles, or senior roles.
How do I adjust the level of my test to match the qualifications of the position I’m trying to fill within my company?
You don’t. Our tests are made with such difficulty in mind, that they would challenge all skill levels regardless of seniority. We almost never see any candidate getting everything correct on our exams.

If you are trying to fill a senior role, you would probably want candidates to score above 60% in Kandio. If you’re looking for a junior role, you could probably settle with 30%-50%

If you want a very junior role, that you can train along the way, you would be looking at 30%-50%.

We wouldn’t recommend considering any candidate below 20% unless you have clear indications from other factors of decision making.