This category is all about SQL interview questions and answers on different SQL concepts such as SQL Functions, Triggers, Commands, comparison concepts like difference between union and union all and difference between unique key and primary key e.t.c.
In this category, we have captured all important SQL concepts with practical examples.
I am sure any beginner can easily understand these concepts.
If you are preparing for an interview, these questions and answers can really boost your knowledge.
Some of them are very frequently asked interview questions such as rank, dense rank, partition e.t.c and some of them are advanced topics.
👨💼 SQL Query to Find Employees Who Didn’t Attend Any Training (LEFT JOIN Example) In real-world HR and analytics systems, it’s often necessary to identify employees who have not attended any training programs. This type of query is useful in employee engagement analytics, compliance tracking, and HR dashboards. We’ll use a simple LEFT JOIN approach … Read more
“`html 🏆 SQL Query to Find Top 3 Salaries Without Using LIMIT or TOP (Step-by-Step Example) Finding the top 3 salaries in SQL is a classic interview and practical database problem. Most developers use the LIMIT (MySQL) or TOP (SQL Server) clause — but what if your system doesn’t support them, or you want a … Read more
⚡ SQL Query to Calculate Running Total Without Window Functions (Step-by-Step Example) Calculating a running total (cumulative sum) is a key task in data reporting, especially for business dashboards, financial reports, and time-based analytics. Modern databases offer SUM() OVER() window functions to handle this easily — but what if your system doesn’t support them? Don’t … Read more
🧠 SQL Query to Find Duplicate Records with Different Values (Real-World Example) Data duplication is one of the most common challenges in database management. Often, you’ll encounter duplicate records with mismatched details — such as the same employee ID appearing with different email addresses or contact numbers. These inconsistencies can cause serious reporting errors in … Read more
SQL Index Usage Visualizer — Suggested Indexes from Your Query Paste a SQL SELECT query below and get recommended index suggestions (e.g. CREATE INDEX statements) & quick optimization tips. This is a **learning & exploratory** tool — all processing happens in your browser. Paste your SQL SELECT query 🔎 Analyze Query & Suggest Indexes Reset … Read more
FAQ Schema Generator – Create Google FAQ JSON-LD Markup Instantly Easily create structured FAQ Schema markup for your blog posts and get rich results in Google Search. Paste your questions and answers, and our tool instantly generates SEO-ready JSON-LD code—no coding required. 💡 What Is an FAQ Schema? An FAQ Schema is a type of … Read more
Interactive Chart & Graph Maker – Visualize Data Instantly Create stunning charts and graphs in seconds. Input or paste your data, choose a chart type, and visualize results instantly—perfect for analysts, Power BI learners, and data enthusiasts. 📊 About the Interactive Chart Tool This Interactive Chart Maker allows you to convert your simple tabular data … Read more
SQL Query Visualizer – Transform SQL Queries into Interactive Diagrams Visualize your SQL queries with a clean, interactive diagram that shows how tables, joins, filters, and aggregations connect. Great for learning or explaining database logic in Power BI and analytics projects. 🔍 Why Use a SQL Query Visualizer? Understanding complex SQL queries can be challenging … Read more