08 AGGREGATE FUNCTIONS ORACLE SQL IN TELUGU | PANDIT AJESH  #sqltelugu #PLSQLTELUGU #AGGREGATE
Channel: PANDIT AJESH
Date: 19/08/2023

Welcome to Pandit Ajesh's YouTube channel!

sql functions with examples
aggregate functions in sql

1.  Understanding Aggregate Functions :
   Aggregate functions perform calculations on a set of values and return a single value as the result. Common aggregate functions include `COUNT`, `SUM`, `AVG`, `MIN`, and `MAX`.

2.  Using Aggregate Functions :
   Aggregate functions are often used with the `SELECT` statement. You can apply them to columns in a table or the result of expressions.

    
   SELECT COUNT(column_name) FROM table_name;
    

3.  Handling NULL Values :
   Most aggregate functions ignore NULL values when performing calculations. If you want to include NULL values in your calculations, you can use the `NVL` function or the `COALESCE` function to replace them with a specific value.

4.  Combining Aggregate Functions :
   You can combine multiple aggregate functions in a single query to get various calculations in one result set. For example:

    
   SELECT COUNT(column_name), AVG(column_name), SUM(column_name) FROM table_name;
    

5.  Using `GROUP BY` with Aggregates :
   The `GROUP BY` clause divides the result set into groups based on one or more columns and applies aggregate functions to each group individually. This is useful for summary reports.

    
   SELECT department_id, AVG(salary) FROM employees GROUP BY department_id;
    

6.  Filtering Groups with `HAVING` :
   When using `GROUP BY`, you can use the `HAVING` clause to filter groups based on aggregate conditions, similar to the `WHERE` clause for individual rows.

    
   SELECT department_id, AVG(salary) FROM employees GROUP BY department_id HAVING AVG(salary)  grater than 50000;
    

7.  Using Analytic Functions :
   Analytic functions (`ROW_NUMBER`, `RANK`, `DENSE_RANK`, etc.) can work alongside aggregate functions to perform calculations based on the entire result set or groups, without using `GROUP BY`.

8.  Nesting Aggregate Functions :
   You can nest aggregate functions, but be cautious about the order of evaluation. Aggregate functions within an outer function are computed for each row, not after the outer function is computed.

9.  Performance Considerations :
   Aggregate functions can impact performance, especially when used with large datasets. Proper indexing and query optimization are important to ensure efficient execution.

10.  Subqueries and Aggregate Functions :
    You can use subqueries to calculate aggregate values and then use those values in the outer query. This can be useful when you want to compare individual rows to summary statistics.




🔹 About This Channel 🔹
On this channel, you'll find high-quality tutorials and educational content focused on SQL (Structured Query Language) and PL/SQL (Procedural Language/Structured Query Language). Whether you're a beginner or looking to enhance your skills, we've got you covered with easy-to-follow lessons, practical examples, and expert tips.

🔹 What You'll Learn 🔹
✓ SQL Fundamentals and Basics
✓ PL/SQL Programming Techniques
✓ Database Management Concepts
✓ Oracle Database Development
✓ SQL Optimization and Best Practices
✓ Advanced SQL Queries and Joins
✓ PL/SQL Procedures and Functions
✓ Database Design and Development

🔹 Stay Connected 🔹
Make sure to hit the "Subscribe" button and turn on the notification bell 🔔 to never miss an update. Join our growing community of SQL and PL/SQL enthusiasts who are eager to learn and share knowledge.

🔹 Connect with Pandit Ajesh 🔹
Follow me on social media and stay updated with the latest announcements, behind-the-scenes, and more:
📷 Instagram: https://www.instagram.com/ajeshraylu/
🐦 Twitter: https://twitter.com/ajeshroyal
 🌐 Facebook: https://www.facebook.com/ajeshrayalu

🔹 Contact 🔹
For business inquiries, collaboration opportunities, or any questions related to the content, you can reach me at [Your Email Address].

🔹 Share Your Feedback 🔹
Your feedback is invaluable to me! Feel free to leave your thoughts, suggestions, and topic requests in the comments section. Your input helps shape the content and makes this channel even better.

Thanks for visiting Pandit Ajesh's channel! Let's embark on a journey of SQL and PL/SQL excellence together.

#SQL #PLSQL #DatabaseManagement #OracleDatabase #SQLTutorials #Programming