Unlock the power of SQL subqueries while avoiding common pitfalls that can lead to complex and inefficient queries. In this video, we dive deep into subqueries and explore how they can simplify your SQL code-or hurt your query performance if used incorrectly. I'll walk you through different types of subqueries, like single-row, multi-row, correlated, and scalar subqueries, and show you real-world examples of how to use them effectively.

We'll also tackle the age-old question: Should you use subqueries or joins? And I'll highlight some common performance pitfalls to avoid, especially when working with large datasets.

By the end of this video, you'll know exactly when to use subqueries and how to optimize your SQL queries for maximum performance!

Join the Gambill DataSphere: https://bit.ly/3Y4Nbc9

If you found this breakdown useful, don't forget to like, subscribe, and hit the notification bell for more data engineering insights. Drop your thoughts or longest-running query in the comments below-let's discuss optimization strategies!

SQL Subquery Chapters:
00:00 Subqueries, what are they good for?
00:35 What will you learn?
00:46 What is a subquery
01:16 When / Why to use subqueries
01:35 Single Row / Inline subqueries
02:16 SQL Example of a inline subquery
05:16 Subquery in your from clause (Example in Azure data factory!)
07:48 How do you run just part of your whole query (subquery)
08:37 Troubleshooting ambiguous field errors
09:08 Best Practice to Resolving the ambiguous fields
12:18 Subquery in your where clause!
14:20 When and how to use subqueries
16:16 Nested queries!
16:56 Making your inline subquery efficient!
17:20 What have you learned?