Author: Sai Pradeep Kala
GitHub: @pradeep240604
Email: saipradeep2464@gmail.com

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Task 4: Aggregate Functions and Grouping in SQL

📌 Objective
To gain hands-on experience in summarizing and analyzing tabular data using SQL aggregate functions and grouping techniques.

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🛠️ Tools Used

• DB Browser for SQLite
• MySQL Workbench

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🧠 Learning Outcomes
By completing this task, you will:

• Understand how to use aggregate functions like SUM, COUNT, and AVG.
• Learn how to categorize data using the GROUP BY clause.
• Apply filters to grouped data using the HAVING clause.
• Enhance your data analysis capabilities using SQL.

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🔍 Key Concepts

1. Aggregate Functions
Functions that perform a calculation on a set of values and return a single value:

• SUM(): Adds up the values.
• COUNT(): Counts the number of rows.
• AVG(): Calculates the average of values.
• MIN() / MAX(): Returns the smallest/largest value.

2. GROUP BY Clause
Used to arrange identical data into groups.

3. HAVING Clause
Used to filter records after grouping (unlike WHERE, which filters before grouping).

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📂 Deliverables

✅ SQL Queries Demonstrating:

• Use of SUM, COUNT, AVG on numeric columns.
• Grouping data using GROUP BY.
• Filtering groups using HAVING.

Example SQL snippets:

-- Count the number of orders per customer
SELECT customer_id, COUNT(*) AS total_orders
FROM orders
GROUP BY customer_id;

-- Average order value by product category
SELECT category, AVG(order_total) AS avg_order_value
FROM products
JOIN orders ON products.product_id = orders.product_id
GROUP BY category;

-- Total sales by region with sales over $10,000
SELECT region, SUM(sales) AS total_sales
FROM sales_data
GROUP BY region
HAVING total_sales > 10000;