SQL developer interview questions and tests

Companies typically deal with a huge amount of data stored in databases. As most businesses seek to do even more with their data ion the future, they need SQL specialists who can analyze and access data. That said, you need to be sure that the person you entrust your data with is reliable and has the right skills. In other words, your data is safe only in the hands of a qualified SQL specialist.

SQL developer interview questions and tests verify the level of expertise of the Structured Query Language and some basic concepts of relational databases.

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Technologies covered:

Programming language: SQL

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

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

Choice questions

assessing knowledge of SQL, MongoDB, NoSQL

Code gaps

assessing knowledge of Mongo, 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.

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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.

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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.

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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.

Available in premium plans

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

Choice questions

assessing knowledge of SQL, MongoDB, NoSQL

Code gaps

assessing knowledge of Mongo, 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.

Available in premium plans

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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.

Available in premium plans

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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.

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JUNIOR
Tested skills
Duration
54 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of SQL

Programming task - Level: Easy

Python | DNA Analyzer - Implement a method in Python that generates DNA statistical report.

Available in premium plans

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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.

Available in premium plans

Create account
SENIOR
Tested skills
Duration
45 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of SQL

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.

Available in premium plans

Create account