SQL Avg

The SQL Avg() function returns the average value of a numeric column.

SQL Avg() Function Syntax

SELECT AVG(ColumnName)
FROM tables
WHERE predicates

SQL Avg() Function Example

Table: Employees

Example 1
We want to know the average salary among all employees:

SELECT AVG(Salary) AS "Average salary"
FROM Employees

The result will look like:

Example 2
If we want to select average salary for each department, we can use GROUP BY clause:

SELECT Department, AVG(Salary) AS "Average salary"
FROM Employees
GROUP BY Department

The result will look like:

Example 3
If we want to select highest, lowest and average salary for each department:

SELECT Department
           , MAX(Salary) AS "Highest salary"
           , MIN(Salary) AS "Lowest salary"
           , AVG(Salary) AS "Average salary"
FROM Employees
GROUP BY Department

The result will look like: