Aggregrate function is a function which returns single value by performing a calculation on a set of values.MySQL provides many aggregate functions such as AVG, COUNT, SUM, MIN, MAX, etc.

MIN returns the smallest value in a given column

MIN(expression)
SELECT MIN(marks) FROM result

MAX returns the largest value in a given column

MAX(expression)
SELECT MAX(marks) FROM result

SUM returns the sum of the numeric values in a given column

  SELECT productCode,sum(priceEach * quantityOrdered) total
    FROM orderdetails GROUP by productCode

AVG returns the average value of a given column

SELECT AVG(marks) FROM result AVG(expression)

COUNT returns the total number of values in a given column COUNT(*) returns the number of rows in a table

COUNT(DISTINCT expression)

example:

SELECT COUNT(*) AS totalprice FROM pricetable