# Category: SQL INTERVIEW QUESTIONS

## DIFFERENCE BETWEEN UNION AND UNION ALL

In short, the difference between UNION operator and UNION ALL (UNION vs UNION ALL) operator is UNION gives unique results set in the output even though the combined result …

Lets take a look at differences between INTERVAL and ADD_MONTHS() in Teradata. This post mainly focused on where to use ADD_MONTHS() over INTERVAL function in Teradata. INTERVAL is a …

## PIVOT OCCUPATIONS TABLE DATA QUERY

PROBLEM STATEMENT: Pivot the ‘Occupation’ column in OCCUPATIONS table so that each ‘Name’ is sorted alphabetically and displayed underneath its corresponding Occupation. The output column headers should be Doctor, …

## TOP EARNERS FROM EMPLOYEE SALARY TABLE – QUERY WITH SOLUTION

PROBLEM STATEMENT: We define an employee’s total earnings to be their monthly salary*months worked, and the maximum total earnings to be the maximum total earnings for any employee in …

## BINARY TREE NODES QUESTION AND SOLUTION WITH QUERY

PROBLEM STATEMENT: You are given a table, BTREE, containing two columns: Value and Parent, where ‘Value’ represents the value of a node in Binary Tree, and ‘Parent’ is the …

## NEW COMPANY HIERARCHIES SQL QUERY

PROBLEM STATEMENT: one of the conglomerate corporations just acquired some new companies. Each of the companies follows this hierarchy. Given the table schemas below, write a query to print …

## FIND THE CANCELLATION RATE USING TRIPS AND USERS TABLES

PROBLEM STATEMENT: The Trips table holds all taxi trips. Each trip has a unique Id, while Client_Id and Driver_Id are both foreign keys to the Users_Id at the Users …

## FINDING TOP 3 SALARIES SQL QUERY

The Employee table holds all employees. Every employee has an Id, and there is also a column for the Department Id. ID Name Salary DepartmentId 1 Joe 85000 1 …