Access high-quality customer churn datasets for building predictive models and conducting churn analysis in data science projects. We've scoured the internet for different kinds of customer churn datasets to highlight our favorites in order of difficulty.
In this article, we’ll cover 29 linear regression practice problems based on common interview questions, along with key tips to help you solve them with confidence.
A complete guide to using SUM(CASE WHEN) for conditional aggregation in SQL—covering syntax, examples, dialect differences, and performance best practices.
This guide explains how to perform SQL joins on multiple columns with examples, real-world use cases, and optimization techniques across major SQL dialects.
This guide explains how to use SQL CASE WHEN with multiple conditions across major databases like MySQL, PostgreSQL, SQL Server, and Oracle. You’ll learn syntax patterns, real-world examples, and practical tips—plus interview-style questions to help you s
A complete 2025 guide to SQL scenario-based interview questions with real-world examples, answers, and platform-specific strategies from beginner to advanced levels.
After graduation, Alma Chen worked as an Actuarial Analyst for almost four years. She then turned to Interview Query when she needed to prepare for her career change, and within three months she had two solid offers.
If you are currently exploring product analytics for the first time, or looking to improve your understanding, then this guide is for you.
In this success story, we’ll explore how Dania transitioned from working in HR to attending OSU's data science program, and ultimately being hired for her very first data science position.
This guide outlines 21 practical AI projects—across NLP, computer vision, healthcare, finance, and LLM applications—complete with datasets, tools, and resume tips to help you build a job-ready AI engineering portfolio.
This week, we've talked with Muhammad Imran Haider, and explored how he transitioned from doing financial analysis for commercial projects to practicing data science at Credit Expert.
In this article, we'll discuss optimization strategies to tackle SQL multiple joins efficiently. But first, let's explore common challenges in query optimization.