Databases for Business Analytics

A brief introductory course to relational databases and SQL, targeting people interested in learning SQL for data analysis. This course does not cover database administration topics such as indexing, transactions, or stored procedures.

Platform: Google BigQuery
Datasets: nyu-datasets.imdb and nyu-datasets.facebook

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Course Videos

Full YouTube Playlist

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Modules

Module 1: Entity-Relationship Model and Relational Databases

• Entities, Primary Keys, and Attributes
• Relations and Cardinality (One-to-One, One-to-Many, Many-to-Many)
• From ER Diagram to Relational Schema
• SQL Statements for Creating Tables

Module 2: Selection & Filtering Queries

• Navigating a Database
• Selection queries: SELECT, AS, DISTINCT, ORDER BY, LIMIT
• Filtering with WHERE: Boolean operators, IN, LIKE, BETWEEN
• Handling NULL values
• Conditional logic with CASE WHEN
• Attribute-level functions: string, date, and NULL functions

Module 3: JOIN Queries

• Inner Joins
• Self Joins
• Outer Joins (LEFT, RIGHT, FULL)
• Semi-joins and Anti-joins

Module 4: Aggregate Queries

• Aggregation functions: COUNT, SUM, AVG, MAX, MIN, STDEV
• GROUP BY on single and multiple attributes
• Filtering groups with HAVING
• Combining JOINs and GROUP BY

Module 5: Subqueries

• Subqueries with single-value results
• Semi-joins and Anti-joins using IN
• Derived tables
• WITH clause (Common Table Expressions)
• Comparison: CTEs vs. temporary tables vs. views

Module 6: Window Functions

• Window definition: OVER(ORDER BY)
• Ranking functions: RANK, DENSE_RANK, ROW_NUMBER
• Partitioned windows: OVER(PARTITION BY ... ORDER BY ...)
• Offset functions: LEAD, LAG, FIRST_VALUE, LAST_VALUE
• Frame definitions and rolling aggregations

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Additional Resources

Practice Platforms

• StrataScratch — SQL interview questions from tech companies
• LeetCode Database Problems
• DataLemur — SQL interview prep
• W3Resource SQL Exercises

Tutorials

• Mode SQL Tutorial — Basics to advanced
• Khan Academy: Introduction to SQL — Video-based intro
• W3Schools SQL — Hands-on examples
• Codecademy: Learn SQL
• How to Teach People SQL — Great visualizations

Books & Guides

• Learning MySQL — Comprehensive textbook
• Become a SELECT Star! by Julia Evans — Visual SQL zine
• SQL Data Manipulation for Data Scientists — Advanced techniques
• SQL Best Practices — Writing readable SQL

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Setup

All notebooks use Google BigQuery. To run them:

1. Open any notebook in Google Colab (use the badge above)
2. Authenticate with your Google account
3. Replace 'your-project-id' with your Google Cloud project ID

The queries use publicly accessible datasets in the nyu-datasets project.