SQL COUNT(), AVG() and SUM() Function (original) (raw)

Last Updated : 13 Aug, 2025

SQL aggregate functions, such as COUNT(), AVG(), and SUM(), are essential tools for performing mathematical and statistical analysis on data. They allow you to:

• Calculate totals
• Find averages
• Count specific rows

These functions are commonly used for data analytics and reporting, enabling deeper insights into datasets.

**SQL COUNT() Function

The COUNT() function provides the number of rows that match a specified condition. It is often used to determine:

• Total records in a table
• Records that meet a specific filter

**Syntax:

SELECT COUNT(column_name) FROM table_name WHERE condition;

**SQL AVG() Function

The AVG() function provides the average value of a numeric column, helping you determine central tendencies in your data. This is useful for understanding the mean value of a set of numbers, such as salaries, prices, or scores.

**Syntax:

SELECT AVG(column_name) FROM table_name WHERE condition;

**SQL SUM() Function

The SUM() function calculates the total sum of a numeric column. It is ideal for calculating:

• Total sales
• Total revenue
• Any cumulative numeric value

**Syntax:

SELECT SUM(column_name) FROM table_name WHERE condition;

Practical SQL Examples

Let us look at some examples of the COUNT(), AVG() and SUM() Function in SQL to understand them better. To demonstrate this, let us create a table "GeeksTab".

CREATE TABLE GeeksTab ( Name VARCHAR(50), City VARCHAR(50), Salary INT, ID INT, DOJ VARCHAR(50) );

INSERT INTO GeeksTab (Name, City, Salary, ID, DOJ) VALUES ('Abc', 'Delhi', 4500, 134, '6-Aug'), ('Dfe', 'Noida', 6500, 245, '4-March'), ('Def', 'Jaipur', 5400, 546, '2-July'), ('Mno', 'Noida', 7800, 432, '7-June'), ('Jkl', 'Jaipur', 5400, 768, '9-July'), ('Lmn', 'Delhi', 7800, 987, '8-June'), ('Ijk', 'Jaipur', 6700, 654, '5-June');

**Table GeeksTab:

**Example 1: COUNT() Function

The following SQL statement finds the number of Names in the "GeeksTab" table.

**Query:

SELECT COUNT(Name) FROM GeeksTab;

**Output:

7

**Example 2: AVG() Function

The following SQL statement finds the average price of salary in the "GeeksTab" table.

**Query:

SELECT AVG(Salary) FROM GeeksTab;

**Output:

6300

**Example 3: SUM() Function

The following SQL statement will find the sum of the Salary in the "GeeksTab" table.

**Query:

SELECT SUM(Salary) FROM GeeksTab;

**Output:

44100

Quick Facts

1. These functions ignore NULL values in calculations.

2. COUNT() counts rows, not values — unless specified with a column name.

3. Can be combined with:

• **WHERE – to filter results
• **GROUP BY – to group results
• **HAVING – to filter aggregated results

4. Widely used in data analysis, reporting, and dashboards.

5. Always ensure data type compatibility for AVG() and SUM() (numeric columns only).