I resolved all the database questions on Leetcode.com recently. The questions cover most of the SQL common queries inlcuding JOIN, Ranking and other SQL basics. I provided the answers as well as explanations in this blog, as a way to consolidate the SQL knowledge.

The questions on Leetcode only support MySQL, so you can install MySQL on your laptop for testing purpose before submitting the solution, or use online SQL platforms to test you query. E.g. rextester more ...

This is an introduction of using NumPy and Pandas based on the course Intro to Data Analysis on Udacity. It includes NumPy and Pandas data structures, basic operations and functions with code examples.. I learnt a lot from this course and shared this notes for your reference.

Table of Contents¶