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SQL online tests

DevSkiller SQL online tests were written by our dedicated team to assess SQL developer skills for various positions. Our SQL coding tests are the perfect solution for all of your technical screening and online interview needs.

Powered by the RealLifeTesting™ methodology, you can use DevSkiller to test candidates for junior, middle, and senior positions.

Technologies covered:

Programming language: SQL

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

Build tools:MSBuild

Solidity
MIDDLE
Tested skills
Duration
70 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Anonymity, Blockchain, Decentralization, DLT, Leger, Ether, Accounts, Ethereum

Programming task - Level: Medium

Blockchain | Solidity | Lottery - Implement the one time raffle based on blockchain technology.

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

Choice questions

assessing knowledge of Math, Probability, Soft Skills, SQL

Code gaps

assessing knowledge of MySQL, SQL

Task - Level: Medium

SQL | MySQL | Software House | Devs and their projects - The Head of the development team assigned you a task to create a list of developers with their role in the ongoing projects.

Node.JS
MIDDLE
Tested skills
Duration
87 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of JavaScript, Node.JS

Code gaps

assessing knowledge of JavaScript, Node.JS, SQL

Programming task - Level: Medium

Node.JS | Rest API | News backend service - Implement a news backend service created in Node.JS with Vanilla JS including writing authorization and Rest APIs.

SQL
JUNIOR
Tested skills
Duration
25 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Logical thinking, Math, MySQL, SQL

Code gaps

assessing knowledge of SQL

Task - Level: Easy

SQL | MySQL | Stamps catalogue | AVG Function - Select the stamps (name and price) with price greater than or equal to the total average price.

SQL
JUNIOR
Tested skills
Duration
33 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Logical thinking, SQL, MySQL

Code gaps

assessing knowledge of MySQL, SQL

Task - Level: Easy

SQL | MySQL | Stamps catalogue | A Self JOIN - Select stamps (name and location) that are in the same location.

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

Choice questions

assessing knowledge of SQL, PostgreSQL

Code gaps

assessing knowledge of PostgreSQL, SQL

Task - Level: Medium

SQL | PostgreSQL | Music Store | Time function - Calculate the duration of all songs in each cd and output a list.

SQL
JUNIOR
Tested skills
Duration
26 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Logical thinking, SQL

Code gaps

assessing knowledge of SQL

Task - Level: Easy

SQL | PostgreSQL | Hotels - average prices - Prepare the report with the average prices in the cities.

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

Choice questions

assessing knowledge of Logical thinking, SQL

Code gaps

assessing knowledge of SQL

Task - Level: Easy

SQL | PostgreSQL | Hotels - bookings - Prepare the booking list with a number of days, price per day and total price of the stay.

SQL
SENIOR
Tested skills
Duration
52 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Logical thinking, SQL

Task - Level: Hard

SQL | PostgreSQL | Hotels - cities and top hotels - Prepare a list of cities with the date of last reservation and a main photo (photos[0]) of the most popular (by number of bookings) hotel in this city.

terraform
JUNIOR
Tested skills
Duration
69 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of DevOps, Terraform, AWS

Code gaps

assessing knowledge of DevOps, Terraform, AWS

Programming task - Level: Easy

DevOps | Terraform, AWS | Create the EC2 instance using specific AMI - Create the EC2 instance using specific AMI in a default VPC with SSH access, using Terraform and AWS provider.

Java
MIDDLE
Tested skills
Duration
57 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of Java, Spring Boot

Code gaps

assessing knowledge of PostgreSQL, SQL

Programming task - Level: Medium

Java | Spring Boot | Items Retriever Microservice - Implement a microservice to retrieve items from the shopping system.

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.

The right SQL online tests to screen SQL developers

Recommended roles for our SQL online tests

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

How our SQL online tests work

The RealLifeTesting™ methodology powers DevSkiller SQL coding tests. Our selection of coding tests will help you analyze your applicants’ knowledge of various SQL versions. In addition to that, our coding tests will help you assess applicants’ coding skills, problem-solving ability, and time management.

Key features

  • DevSkiller SQL coding tests measure applicants’ coding ability and not just their academic knowledge
  • Remote testing that gives you the freedom and convenience of testing candidates from all over the world
  • The RealLifeTesting™ methodology creates a better user experience where candidates can use their own IDE, clone to GIT, run unit tests and access Stack Overlow/Github/Google for research
  • Strict anti-plagiarism tool that ensures accurate test results
  • Automatically generated results that non-tech professionals can understand
  • SQL coding tests available for junior, middle, and senior-level positions

What to look for in SQL developers

SQL is the most popular 4GL (Fourth Generation Programming Language), which means that programmers only declare what the result looks like, rather than how the database should calculate the result. SQL is embedded in other, more general-purpose programming languages like Java to access data from central databases.

A qualified SQL developer should possess well-versed abilities with SQL performance. In addition to this, your successful candidate should possess SQL design skills with demonstrated knowledge of relational theory. Finally, SQL refactoring skills can prove quite useful in larger teams where the SQL is more complex.

Skills covered in our SQL online tests

  • HSQLDB
  • Mongo
  • MongoDB
  • MSSQL
  • MySQL
  • NoSQL
  • Oracle
  • PostgreSQL
  • SQL
  • CSS
  • ES6
  • HTML
  • Javascript
  • PDO

Looks good, but want more?

Do you want to run coding tests in a predefined environment? Perhaps you want to test applicants using your own codebase? At DevSkiller, you can build custom tests using our online task wizard. Solve all of your technical screening needs with our SQL coding tests today.

Want proof that our SQL online tests work?

How can you be expected to understand how effective our screening tool is if you’ve never tried it? After all, our DevSkiller SQL online tests are different to the traditional algorithmic tests you will have encountered. Don’t take our word for it, have a look at what some of our past customers have to say:

Patrycja Kiljańska – Talent acquisition specialist at Spartez

“We’ve replaced a high-maintenance in-house solution with DevSkiller. Our process looks the same, however, the product gives us better performance. The results are also way easier to assess.”

Michael Gerwig Engineering manager at Ada Health

“DevSkiller helped us to save precious on-site time for applicants that are already likely to be a fit. We’re saving 3 hours per candidate – that was the time we spent with applicants on a technical task before.”

Jonatan Rugarn – CEO, Founder, Recruiter at Lingonberry Talent Acquisition, Engineering Manager at Avinode Group

“The duration of the recruitment process has not changed, but we spend less time and effort per candidate. We also don’t waste time on the wrong candidates.”

Frequently asked questions

How are SQL online tests evaluated?

One of the main advantages of DevSkiller testing is that evaluation of our SQL online tests happens automatically. As soon as the candidate is finished, our screening tool gets to work on the solutions and automatically assesses how well each candidate has done. This saves recruiters countless arduous hours spent marking algorithm tests.

Candidates are assessed on whether or not the solution they came up with would run (an essential factor in all software development). How their solution would perform in edge cases and the content and quality of their code. Successful candidates are those who can best demonstrate their critical thinking skills in the time allotted.

Results are then compiled into concise, easy-to-follow reports, that non-technical professionals can understand regardless of their own level of technical skill.

How do candidates take an SQL online test?

Devskiller SQL online tests are accessed remotely and can be taken from anywhere in the world. Saving valuable time spent waiting until both the candidate and the interviewer have time to conduct a test. Remote-testing means once the test invites are sent, the recruiter just has to sit back and wait for the results to come in. Recruiters can even add time limits to each test to make sure they’re not left waiting around.

When it comes to the test itself, candidates have the option of using DevSkiller’s state-of-the-art in-browser IDE or they can complete the project on their favorite IDE and then clone the project to GIT. If they want, candidates can run unit tests to make sure their solutions work the way they are supposed to.

What’s the duration of SQL online tests?

The duration of our SQL online tests is flexible and is left up to the recruiter. Each SQL test comes loaded with default settings, including a default duration, but these can be easily adjusted. Even individual questions within a test can be given time limits if required.

What do candidates think of DevSkiller SQL online tests?

Developers’ reactions to our SQL online tests are by and large, very positive. The vast majority of candidates relish the chance to prove their software development skills. If occasionally, a developer’s reaction is not as we expect,  this is usually just an initial reaction to having to take the tests at all. Many developer tests don’t reflect the real work that developers actually do, so they can grow wary of developer testing. Once they realize our tests are different, they’re overwhelmingly positive in their responses and love the chance to actually show what they can do.

Our SQL online tests allow developers to use normal coding tools and conventions like unit testing and cloning to GIT from a personal IDE.