SQL AVG() Function

The AVG() Function

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

SQL AVG() Syntax

SELECT AVG(column_name) FROM table_name

SQL AVG() Example

We have the following "Result" table:

Student_No	Subject_No	Year_Exam	Marks
ST101	SU03	1	69
ST102	SU01	1	61
ST101	SU04	1	70
ST101	SU05	1	87
ST103	SU01	2	51
ST103	SU03	1	59
ST103	SU01	3	56
ST108	SU01	1	78
ST105	SU05	2	98

Now we want to find the average value of the "Marks" fields.

We use the following SQL statement:

SELECT AVG(Marks) FROM result;

The result-set will look like this:

AVG(Marks)

69.8889

Now we want to find the every student  average Marks value.

We use the following SQL statement:

SELECT Student_No,AVG(Marks) FROM result GROUP BY Student_No;

The result-set will look like this:

Student_No	AVG(Marks)
ST101	75.3333
ST102	61.0000
ST103	55.3333
ST105	98.0000
ST108	78.0000