Data Science Educational Resources
StrataScratch is a data science educational platform with over 1,000+ real interview questions from your favorite companies.
Interviews
How to Drop Duplicates in PySpark?
Learn how to ensure accurate analysis by identifying and removing duplicates in PySpark, using practical examples and best practices for handling large datasets.
Nathan Rosidi -
How to Use SQL Wildcards for Flexible Data Queries
This article is all about uncertainty and using it to add flexibility to SQL queries. How do you do that? Start using one of the five SQL wildcards regularly.Nathan Rosidi -
How Does SQL Date Formatting Work?
In this article, we explore the SQL date format. We’ll deal with how standard and custom date formatting work in four of the most popular SQL flavors.Nathan Rosidi -
Simplifying SQL Queries with Aliases: A How-To Guide
SQL aliases are a simple yet efficient way of simplifying your SQL queries. In this guide, we’ll show you all the benefits and provide examples of their use.Nathan Rosidi -
Data Type Conversion in SQL: A Closer Look at CAST Function
Master data type conversion: why do it, how to do it, and how not to do it. The article covers all that with some real-world examples from the platform.
Tihomir Babic -
SELECT UNIQUE in SQL: Mastering Data Retrieval with DISTINCT
What is SELECT UNIQUE in SQL? What about SELECT DISTINCT? How do you retrieve unique data? We will answer these three and more questions in this article.Nathan Rosidi -
Python String Methods: Here is How to Master Them
Explore practical examples, learn how to effectively clean and format strings, and harness the power of Python’s memory model to master string operations.Nathan Rosidi -
A Detailed Comparison Between Inner Join vs. Outer Joins
In this article, we compare inner join vs. outer join. We will talk about their similarities and differences and show you how to use them in practice.Nathan Rosidi -
Top 15 SQL Server DBA Interview Questions
SQL Server DBA interviews: writing window functions, retention queries, explaining indexing internals and isolation levels.
Sara Nobrega -
SQL ROW_NUMBER() Function: Syntax and Applications
How to add SQL ROW_NUMBER() to your data handling and analysis tools? We’ll help you by explaining its workings, its syntax, and how to use it in examples.Nathan Rosidi -
MS SQL vs MySQL: Similarities and Differences
Facing the choice of MS SQL vs MySQL? Here’s a guide through the similarities and differences of these two popular database systems.Nathan Rosidi -
Understanding SQL's INTERSECT Command
What is INTERSECT in SQL? How does it work? When to use it? How to write an INTERSECT query? You can find all these questions answered in this article.Nathan Rosidi -