SQL developer interview questions and tests

DevSkiller specializes in creating SQL developer interview questions aimed at recruiting only the best SQL engineers. Our tests are uniquely structured to assess the skills of candidates of any level.

You may have heard of RealLifeTesting™. A unique testing methodology used to replicate real-world scenarios and present candidates with realistic challenges, similar to those they face every day. It is implemented into all of our developer tests to ensure our clients hire only the best developers. Find your next SQL developer with our range of SQL developer interview questions.

Technologies covered:

Programming language: SQL

SQL frameworks and libraries: MySQL, PostgreSQL, Oracle, MSSQL and others

SQL
MIDDLE
Tested skills
Duration
65 minutes max.
Evaluation
Automatic
Test overview

Database task - Level: Medium

SQL | MSSQL | Finding nulls - Write a query that returns the names of all items which are not available

Database task - Level: Medium

SQL | MSSQL | Finding date ranges - Write a query that returns the names of all items added within the last 7 days.

Database task - Level: Medium

SQL | MSSQL | Using aggregates - Write a query that returns the names of all items of a given category

Database task - Level: Medium

SQL | MSSQL | Finding duplicates - Write a query that returns the names of all items which are duplicated

Python
SENIOR
Tested skills
Duration
82 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Big Data, PySpark, Python

Code gaps

assessing knowledge of SQL

Programming task - Level: Hard

Python | PySpark | Fleet management corporation - Detect speeding events and verify correctness of an existing predictor.

Java
JUNIOR
Tested skills
Duration
120 minutes max.
Evaluation
Automatic
Test overview

Front End programming task - Level: Easy

JavaScript | TypeScript | Invoice application - frontend - Implement the front-end part for merging and aggregating the invoice data with currency exchange rates.

Back End programming task - Level: Easy

Java | Invoice application - backend - Implement the backend part for searching and aggregating invoice data with the service and the DAO methods.

Data Science
JUNIOR
Tested skills
Duration
45 minutes max.
Evaluation
Automatic
Test overview

Task - Level: Easy

SQL | Stamps catalogue | The three highest prices - Select three stamps (price and name) with the highest price.

Programming task - Level: Easy

Python | Pandas | HTML table parser - Implement a function to convert HTML table into a CSV-format file.

Python
MIDDLE
Tested skills
Duration
120 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Python

Programming task - Level: Medium

Python | Vehicle sales report - Implement an application to create reports based on the vehicle sales data warehouse.

DevOps
SENIOR
Tested skills
Duration
66 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of DevOps, Docker

DevOps task - Level: Hard

DevOps | Master of Disaster Recovery (CentOS) - Recover data from broken MariaDB/MySQL database.

DevOps
SENIOR
Tested skills
Duration
66 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of DevOps, Docker

DevOps task - Level: Hard

DevOps | Master of Disaster Recovery (Ubuntu) - Recover data from broken MariaDB/MySQL database.

PostgreSQL
MIDDLE
Tested skills
Duration
44 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of SQL

Code gaps

assessing knowledge of SQL

Task - Level: Medium

SQL | PostgreSQL | Hotels - hotels page optimization - Improve the performance of the the hotels listing page which currently uses ORM.

MongoDB
MIDDLE
Tested skills
Duration
51 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of SQL, MongoDB, NoSQL

Code gaps

assessing knowledge of MongoDB

Task - Level: Medium

SQL | Customer Data - Find all the customers whose first and last names are not unique in this database, as well as the number of times each first and last name pair appears in the database.

PHP
MIDDLE
Tested skills
Duration
60 minutes max.
Evaluation
Automatic
Test overview

Code gaps

assessing knowledge of SQL

Choice questions

assessing knowledge of ES6, JavaScript, CSS, HTML, WCAG 2.0, Web Accessibility

Programming task - Level: Medium

PHP | Categories Repository - Implement PDO queries that will return valid results about movies to users.

PHP
SENIOR
Tested skills
Duration
88 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of SQL, ES6, JavaScript, AJAX, Web development

Programming task - Level: Hard

PHP | XML-CSV Converter - Implement filtering and data transformation methods to pass all the tests.

PHP
JUNIOR
Tested skills
Duration
41 minutes max.
Evaluation
Automatic
Test overview

Code gaps

assessing knowledge of SQL, CSS, HTML

Choice questions

assessing knowledge of JavaScript

Programming task - Level: Easy

PHP | Faker | Basic data manipulation - Implement all the methods in the app/Faker class.

MongoDB
SENIOR
Tested skills
Duration
56 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of SQL, MongoDB, NoSQL

Code gaps

assessing knowledge of MongoDB

Task - Level: Hard

SQL | Fill sparse table - Write a query that will return the list of all users with the creation date and return the date from the previous not-null row for the entries affected with the bug.

MongoDB
JUNIOR
Tested skills
Duration
27 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of SQL, MongoDB, NoSQL

Code gaps

assessing knowledge of MongoDB, SQL

Task - Level: Easy

SQL | Stamps catalogue | CASE statement - Make a select statement, by which you will divide your stamps collection into 3 groups.

NumPy
MIDDLE
Tested skills
Duration
80 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of *SQL

Programming task - Level: Medium

Python | NumPy | Aircraft measurement data processing - Complete data processing application that aggregates and compresses data streams using NumPy, Python and Data Analysis.

MIDDLE
Tested skills
Duration
40 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of SQL, MySQL

Task - Level: Medium

SQL | Customer Data - Find all the customers whose first and last names are not unique in this database, as well as the number of times each first and last name pair appears in the database.

Recommended roles for SQL online tests

  • Data analyst
  • Database administrator
  • Database engineer
  • Database specialist
  • Junior SQL developer
  • Middle SQL developer
  • Senior SQL developer
  • Data entry technician
  • Data quality specialist

How DevSkiller SQL developer interview questions and tests work

The driving force behind DevSkiller’s SQL developer interview questions and tests is the RealLifeTesting™ methodology. It allows DevSkiller to create a simulated version of reality in order to test developer candidates with realistic challenges similar to the work they do every day. With our SQL developer interview questions and tests you can analyze your applicants’ knowledge of SQL, assess their coding ability, test their problem-solving, and time-management skills.

Key features

  • Gain insight into each candidate’s coding skills, not just their academic knowledge
  • Assess each SQL online test in real-time, anywhere in the world
  • RealLifeTesting™ methodology offers a greater user experience where candidates can use their own IDE, clone to Git, run unit tests, and access Stack Overflow/GitHub/Google for research
  • Various anti-plagiarism tools to ensure test accuracy
  • Automated results that non-technical professionals can understand
  • SQL developer interview questions and tests to assess any level

Skills covered in our SQL developer interview questions and tests

  • Hibernate
  • Java
  • Java Stream API
  • JavaScript
  • SQL
  • TypeScript
  • Data analysis
  • HSQLDB
  • MySQL
  • Pandas
  • Python
  • Data Analysis with Python
  • data science
  • SQLite
  • CentOS
  • DevOps
  • Docker
  • Linux
  • MariaDB
  • Ubuntu
  • PostgreSQL
  • Mongo
  • MongoDB
  • MSSQL
  • NoSQL
  • Oracle
  • AJAX
  • ES6
  • JavaScript
  • PHP
  • PHP 7 tests online
  • Web development
  • CSS
  • JavaScript
  • Vhtml
  • data science
  • NumPy
  • Python 3.x
  • Django

What to look for in an SQL developer

SQL is a 4th Generation Programming Language (4GL). Basically, this means that programmers only declare what the result looks like, rather than how the database should calculate the result. SQL uses more general-purpose programming languages like Java to access data from central databases.

The right SQL candidate should possess a good knowledge of SQL, including the subtleties and the nuances of its performance. They should possess skills in SQL design and relational theory. Finally, any demonstrable skills in SQL refactoring will come in handy in larger teams where the SQL is more complex.

Want to get more out of our SQL developer interview questions and tests?

Perhaps your business needs require you to get more out of our SQL online tests. If so, then you can customize our SQL developer interview questions and tests to fit your recruitment agenda. You can set the difficulty level, length, and even question duration on each individual test.  You can monitor applicants in real-time and our plagiarism detectors ensure test validity. Find your next SQL engineer with DevSkiller’s SQL developer interview questions and online tests.

Want proof that our SQL developer interview questions and tests work?

If you think our screening tool sounds great, but you’re a little unsure. No problem. Some of our past clients felt the same way as you, to begin with. Read the following case study to learn how we helped them:

Ada Health

Ada is a global health company. Their core system connects medical knowledge with intelligent technology to help people manage their health and for medical professionals to deliver effective care.

The company requires skill in technologies such as Kotlin, Java, React Native, and many more.  Previously Ada screened technological skills through an on-site task, followed by a team interview. The whole procedure was laborious and time-consuming so they enlisted DevSkiller’s help.

Thanks to DevSkiller, Ada ar now able to gain a broader understanding of each candidate’s experience from an initial technical task, which is carried out prior to interviews taking place. Evaluation for DevSkiller testing is automated, which saves countless hours of time for Ada’s recruitment employees.

Michael Gerwig – Engineering manager at Ada Health

“Not only do we save a considerable amount of time, but the tool also gives us the possibility to collaborate on reviewing the technical test. It also enables us to tailor the on-site experience towards the candidate, for example, which areas to focus on or how difficult the questions should be. Overall, the feedback has been quite positive. Candidates especially enjoy the Code Review task.”

Frequently asked questions

Do I need to be a programmer to use DevSkiller?

Don’t worry, you’re not expected to be a technical expert yourself to be able to use DevSkiller. Our own experts have created ready-to-use SQL developer interview questions and tests which are specially designed to be easy for recruiters to get the best out of. This means you can verify the technical skills of the candidates screened regardless of your own level of technological skill. You can prepare a test from scratch if required.

What do you do about plagiarism?

You need to be able to trust your results, so at DevSkiller we take plagiarism very seriously. We employ a number of anti-plagiarism tools designed to catch any cheats in the act. We can implement screen recording to check if the candidate is looking at a different screen when undertaking a test, as well as a range of social listening tools. We can also check the candidate’s entered code, question duration, and the way each question was answered. Our database stores answers previously provided, which are cross-checked against new answers coming in. If there is a match it will flag that the candidate has tried to gain an unfair advantage.

How do candidates respond to DevSkiller SQL developer interview questions and tests?

We have received regular feedback from developer candidates that they love the structure of our SQL developer interview questions. It is important to understand that more often than not, developer testing involves candidates having to recite coding patterns and algorithms. This can frustrate developers because this doesn’t assess their actual development skills and could result in a lesser skilled developer progressing, simply because they happen to remember a coding pattern. We don’t leave anything to chance. Our SQL developer interview questions and tests challenge candidates with tasks exactly like the work they’ll be doing.

In turn we hear that candidates relish having the chance to use normal coding tools and conventions like unit testing, and cloning to GIT from a personal IDE. We give developer candidates a chance to demonstrate what they can really do within a fair setting and for that they are thankful.

What is the test duration?

The duration of our SQL developer interview questions and tests is flexible. Duration can be set to your own preferences if required. We provide default settings which can be altered. It is also possible to set time limits for individual questions within a test.

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