Blog Archives
1 2 3 4

21: 50+ SQL scenarios based interview Q&As on distinct count of all columns

We all know how to get a distinct count of a column. It can be done with COUNT(DISTINCT column_name). For example:



22: 50+ SQL scenarios based interview Q&As on recursion

This extends Common Table Expressions (i.e. CTE) in SQL using the “WITH” clause. You can try the example on DB Fiddle. Use MySQL v8.0 or later. Scenario: 1 Given a …



23: 50+ SQL scenarios based interview Q&As – Join counts

One of the common SQL interview questions is to quiz your understanding of SQL joins. In this let’s look at joins example with two scenarios.

Venn Diagram

Joins can …



24: 50+ SQL scenarios based interview Q&As – Window Query

If you want to learn the basics of SQL analytics function, first read SQL analytic functions interview questions – Part 1 | SQL analytic functions interview questions – Part 2



25: 50+ SQL scenarios based interview Q&As – get the last non null value

The below SQL problem can be practiced on MySQL database at db-fiddle or database of your choice. Q1. Given the below data, how will you find the last non null …



25+ SQL interview questions & answers – beginner

SQL interview Questions & Answers is a must for any developer as all non-trivial applications need to talk to a database with CRUD operations. Q3 – Q15 are very popular …



25+ SQL interview questions & answers – intermediate to experienced

This continues 25+ SQL interview questions & answers – beginner

Q16. Why do you have CASE statements in SQL?
A16. CASE statements in SQL are similar to IF and ELSE …



26: 50+ SQL scenarios based interview Q&As – number of logins by transaction count

Setup the data on db-fiddle MySQL V8.0 to practice. This question is based on the LeetCode SQL problem Q. Given the below input: login table



26: 50+ SQL scenarios based interview Q&As – Window function (i.e. OVER(…)) with GROUP BY

The below SQL problem can be practiced on MySQL database at db-fiddle or database of your choice. Use latest version from the drop down.

Q1. Given the below data, how …



27: 50+ SQL scenarios based interview Q&As – identifying consecutive records – job status repetition

The data analysts & engineers will often be faced with the below SQL scenario at work. It is also often asked in job interviews. This solution uses SQL analytical functions …



28: 50+ SQL scenarios based interview Q&As – identifying consecutive logins

This extends 50+ SQL scenarios based interview Q&As – identifying consecutive records – job status repetition. A popular SQL coding interview question. Setup the data on db-fiddle MySQL V8.0 to …



29: 50+ SQL scenarios based interview Q&As – Non-Equi Join problem

Q01. What is a Non-Equi Join? A01. A Non-Equi Join in SQL that uses operators other than equality operator (i.e. ‘=’), like , = to join two tables. Q02. When …



30: 50+ SQL scenarios based interview Q&As – Data cleaning, quality checks & profiling

This post covers SQL examples to perform quality checks, clean data and profile data. Q01. What is Data Cleaning? Can SQL do data cleaning? A01. Data cleaning is the process …



1 2 3 4

300+ Big Data Interview Questions - FAQs

300+ Java Interview Questions - FAQs

Tutorials on Java & Big Data