PostgreSQL: AVG Function – Calculate the Average Value of a Column

Welcome to The Coding College, your trusted source for coding tutorials! Today, we’ll explore the AVG function in PostgreSQL, which is used to compute the average value of numeric data in a column.

What is the AVG Function?

The AVG function calculates the average of numeric values in a column. It’s particularly useful for analyzing trends, performance metrics, and other data insights.

Syntax

SELECT AVG(column_name)
FROM table_name
[WHERE condition];

• column_name: The column containing numeric data.
• WHERE: (Optional) Filters rows before computing the average.

Example: Sample Table

Let’s use the employees table:

Using the AVG Function

Example 1: Calculate the Average Salary

SELECT AVG(salary) AS average_salary
FROM employees;

Result:

Example 2: Calculate the Average Age

SELECT AVG(age) AS average_age
FROM employees;

Result:

Using AVG with Conditions

Example 3: Average Salary in the IT Department

SELECT AVG(salary) AS average_it_salary
FROM employees
WHERE department = 'IT';

Result:

Combining AVG with GROUP BY

Example 4: Average Salary by Department

SELECT department, AVG(salary) AS average_salary
FROM employees
GROUP BY department;

Result:

Real-World Applications of AVG

1. Salary Analysis: Determine average salaries across departments or industries.
2. Performance Metrics: Calculate the average score, completion time, or sales.
3. Demographic Insights: Compute average age, income, or other demographic details.

Key Points to Remember

• The AVG function ignores NULL values during calculations.
• Use the ROUND() function to format the result for better readability:

SELECT ROUND(AVG(salary), 2) AS rounded_average_salary
FROM employees;

Learn More at The Coding College

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Conclusion

The PostgreSQL AVG function is an indispensable tool for analyzing data and extracting meaningful insights. Whether you’re working on financial data, demographic statistics, or performance metrics, AVG makes it simple to find the average value.

Stay tuned to The Coding College for more PostgreSQL tips and programming tutorials!