Data Analyst

Return data of students who scored more than the average marks
From the given table, return the total count of different severity of Covid among the three age groups, where age groups from the given data were supposed to be created by me using SQL functionalities.
From the given data of 3 tables location, companies, and employees, find out the location with most companies and return the name and company of employees who work in that location
A question where the top 3 records in each category were to be fetched with some other conditions applied (I used Window Functions here). This one had a trick to sorting where I used another Window function to extract an additional column to sort on to get the desired result.

You are given a string 'str' of length 'N'.

Your task is to return the longest palindromic substring. If there are multiple strings, return any.

A substring is a contiguous segment of a string.

For example :

str = "ababc"

The longest palindromic substring of "ababc" is "aba", since "aba" is a palindrome and it is the longest substring of length 3 which is a palindrome. 

There is another palindromic substring of length 3 is "bab". Since starting index of "aba" is less than "bab", so "aba" is the answer.

A table of 4 columns contains duplicate rows. How to extract the duplicate rows?
Two tables A and B have one column “Id” (duplicates allowed), what would be the result of the inner join of these two?
.How to delete duplicates from a SQL table?
Given a table with StudentId, Marks, and SubjectName, find the details of a student with the subject in which they scored lowest each student?
Questions related to the project and basics of Python data structures and libraries like Pandas and NumPy.
COALESCE Function? Explanation and Use?