As we know that database contains a lot of data, therefore it is always hard to get the data summarized if the data size is huge.

Fortunately, SQL provide some aggregate functions to assist with the summarization of huge data.

SQL Aggregate Functions are useful when mathematical operations must be performed from a huge data .

SQL Aggregate Functions are:

COUNT- count a number of rows
SUM- return sum
MAX- return maximum
MIN- return minimum
AVG- return average

The WHERE clause can be used with the quries that use aggregate functions to specify a set of rows that will be included in the function calculation.

The syntax for the aggregate function clause is: