LIMIT and OFFSET in PostgreSQL Queries || Queries in PostgreSQL || Postg...

Welcome to Lesson #40 in our PostgreSQL Full Playlist! In this video, we explore the powerful LIMIT and OFFSET clauses in PostgreSQL and how they help control the number of rows returned from a query. Whether you're building a backend for a web app or optimizing your data reports, mastering these clauses is essential.

We begin by understanding the syntax of LIMIT and OFFSET, followed by real-world examples using an employees table. You’ll learn how to:

• Return a specific number of rows

• Skip rows using OFFSET

• Combine both for pagination

• Use ORDER BY to ensure consistent and predictable results

We’ll also walk through advanced techniques like using CTEs (Common Table Expressions) for more powerful and flexible pagination with ROW_NUMBER().

🔍 Performance Alert: Learn why high OFFSET values can hurt performance and how to implement keyset pagination for large datasets.

Perfect for students, backend developers, and data analysts who want clean, performant SQL!

📌 Chapters:
0:00 - Introduction
1:10 - What is LIMIT and OFFSET?
2:45 - Creating the Employees Table
4:20 - LIMIT Examples
6:00 - OFFSET Examples
7:00 - Pagination with LIMIT & OFFSET
8:00 - Real-World Pagination Scenario
9:20 - Performance Notes & Keyset Pagination
11:00 - Using CTEs with ROW_NUMBER
12:30 - Conclusion

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ORDER BY in PostgreSQL Queries || Sorting Rows in PostgreSQL || PostgreS...

Welcome to video #39 in our PostgreSQL Full Playlist! 🎬 In this tutorial, we dive deep into one of the most essential clauses in SQL: the ORDER BY clause.

You'll learn how to sort query results in PostgreSQL based on one or more columns, expressions, and aliases. We also explain how to handle NULL values using NULLS FIRST and NULLS LAST, sort using column positions, and apply ORDER BY in advanced cases such as UNION, CTEs, and window functions.

Whether you're preparing for interviews, writing production queries, or optimizing reports and dashboards, understanding ORDER BY is critical for clear and consistent output.

We demonstrate everything with real examples and walkthroughs, using a practical employees table. This lesson also includes tips on performance, index use, and sorting text data with collation.

🎯 Topics Covered:

• Basic ascending and descending sorting

• Sorting by expressions like salary + bonus

• Handling NULLs explicitly

• Using column aliases and positions in ORDER BY

• ORDER BY with UNION, DISTINCT, and LIMIT/OFFSET

• Sorting randomly with RANDOM()

• Analytical queries using RANK() with OVER

• Performance tips using EXPLAIN

Make sure to subscribe and check out the full PostgreSQL series for complete mastery! 🚀

📌 Stay tuned for the next episode: LIMIT and OFFSET in PostgreSQL Queries

Combining Queries in PostgreSQL || UNION, INTERSECT, EXCEPT || Best Post...

Welcome to another powerful episode of our PostgreSQL tutorial series! In Video #38, we dive deep into Combining Queries in PostgreSQL using the essential set operators: UNION, INTERSECT, and EXCEPT.

These operators are invaluable when working with multiple result sets. You'll learn:

• How to combine query results with UNION and UNION ALL

• How to find common records across result sets using INTERSECT

• How to exclude records using EXCEPT

• The importance of query compatibility and proper use of parentheses

• How to retain or eliminate duplicates using the ALL keyword

• Practical examples with Employees and Departments tables

We also cover operator precedence, the role of LIMIT and ORDER BY, and how subqueries and aliasing help you write cleaner, more accurate queries.

💡 Whether you're preparing for interviews, learning PostgreSQL for your job, or building data-driven apps, this tutorial is packed with hands-on examples and key tips that will help you query smarter and faster.

🔥 Don’t forget to like, subscribe, and hit the bell icon for more awesome database tutorials every week!

📌 Next up: Sorting Rows in PostgreSQL using ORDER BY!

Select Lists in PostgreSQL || Queries in PostgreSQL || Best PostgreSQL T...

🔍 Welcome to the Ultimate PostgreSQL Tutorial Series!
In this video (#37), we dive deep into one of the most crucial parts of any SQL query—the SELECT list. Whether you're a beginner or brushing up your database skills, this tutorial will guide you through the many ways PostgreSQL lets you customize the data you retrieve.

👨‍💻 What You'll Learn:

• How to select all or specific columns

• Using table aliases for cleaner queries

• Creating computed columns with expressions

• Renaming outputs with column aliases (AS)

• Eliminating duplicates with DISTINCT and DISTINCT ON

• Leveraging subqueries, functions, and CASE expressions

• Working with JSON, arrays, and aggregate functions

• Using LIMIT, OFFSET, and even SELECT without a FROM clause

• Advanced techniques like CTEs (Common Table Expressions)

✨ With practical examples, best practices, and performance tips, this tutorial is your go-to guide for mastering SELECT lists in PostgreSQL!

🧠 Next Video: Combining Queries in PostgreSQL – UNION, INTERSECT, EXCEPT
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Window Functions in PostgreSQL || Queries in PostgreSQL || Best PostgreS...

Welcome to another power-packed tutorial in our PostgreSQL series! 🚀 In Video #36, we dive deep into the world of Window Functions in PostgreSQL — an essential tool for writing analytical queries without losing row-level detail.

💡 Unlike regular aggregate functions, window functions let you calculate SUM, AVG, RANK, ROW_NUMBER, and moving averages over partitions of data while keeping every row visible. This opens up possibilities for advanced reporting, analytics, and insights directly within your SQL.

📊 We walk through real-world use cases with a sales table, showing step-by-step how to:

• Calculate running totals and moving averages

• Assign rankings and row numbers

• Use LEAD and LAG for accessing prior/next rows

• Work with PARTITION BY, ORDER BY, ROWS BETWEEN, and RANGE BETWEEN

• Optimize performance with shared window specs and indexing tips

We even explore NTILE bucketing, filtered aggregations, and how to use GROUP BY alongside window functions.

Whether you're preparing for interviews, working on a data project, or just want to level up your SQL skills — this tutorial is packed with everything you need!

👉 Don’t forget to subscribe, like, and share if you find this helpful. Drop your questions in the comments, and stay tuned for the next video on Select Lists in PostgreSQL.

Happy Querying! 🧠💻

GROUPING SETS, ROLLUP, CUBE Clauses || Queries in PostgreSQL || Best Pos...

In this tutorial, we explore the powerful GROUPING SETS, ROLLUP, and CUBE clauses in PostgreSQL, which are essential for advanced data analysis and reporting. You'll learn how to: Use GROUPING SETS to calculate subtotals across different combinations of dimensions like region, category, and subcategory. Apply ROLLUP to create hierarchical totals—ideal for business summaries (e.g., region → category → subcategory). Use CUBE for full multidimensional aggregation—critical in business intelligence and OLAP scenarios. This video walks through real SQL examples using a sample sales_data table and demonstrates how these clauses simplify complex reporting tasks. If you're working with data warehouses, financial reports, or BI dashboards, mastering these techniques is a must! 👨‍💻 Whether you're a student, analyst, or backend developer, this PostgreSQL video will take your skills to the next level. 📌 Don’t forget to like, subscribe, and check out the full PostgreSQL series!