SQL Query to find out the frequency of each element in a column

This SQL query analyzes the Persons table to determine the frequency distribution of ages. It counts the occurrences of each age and orders them in descending order of frequency.

Suppose we have a table "Person" as below and we need to find out the frequency of each age.

Id	LastName	FirstName	Age	City
1	Smith	John	33	Newyork
2	Smith	Mike	34	Boston
3	Paul	Ryan	39	Chicago
4	William	Brian	45	Baltimore
5	Rao	Sunita	41	Dayton
6	Zing	Sue	33	Owings Mills
7	Smith	Robert	45	Newyork
8	Paul	Zean	33	Chicago
9	Srivastava	Hemant	33	Baltimore
10	Rao	Venkat	45	Dayton

We could find out the frequency distribution by following the SQL query.

SELECT
    Age,
    COUNT(Age) AS Frequency
FROM
    Persons
GROUP BY
    Age
ORDER BY
    COUNT(Age) DESC