Question

Sometimes the question that you want answered involves getting summarized results. For example, you may want to know the total number of Pop/Rock songs/artists that you have in your playlist. Or the average listing price of properties for sale. Or the total number of dogs/cats available for adoption.

A summary query analyzes a set of records and displays summarized results. A summary query works by using an aggregate function.

Aggregate functions perform calculations on a group of records. Several aggregate functions are commonly used in summary queries. The Avg function finds the average value of the field. The Count function counts the number of records that have a value in the field. The Max function finds the maximum value of the field. The Min function finds the minimum value of the field. The Sum function finds the total value of the field.

For this discussion, same as last week, provide an example of when each type is useful. Incorporate examples that relates to your day-to-day life in every aspect you can think of, work, study, household, family, friends, fantasy football, etc.

Answer 1

Hello,
We are not aware who had discussed with last week, we do get the discussion topics randomly so as per my understanding if you are looking for query in oracle i have mentioned below the examples and their explanation.Kindly let me know if you are looking for something else so we can again help you on it.

Below are the queries and explanation:

Basically for finding the pop/Rock/Artists from your playlist:

We can use the follwing Oracle Query:

SELECT pop FROM Playlist; --Display all the pop songs from playlist table.
SELECT count(pop) FROM playlist; -- Displays the total count of pop songs from playlist table.

or SELECT Count(*) from playlist; -- Displays number of playlist.
SELECT count(songs) from playlist; -- Displays the number of songs from playlist.

Similarly we can get it for Rock songs and artists details from the playlist table.

eg: SELECT rock FROM playlist; --
SELECT count(Rock) from playlist;-- Displays count of rock songs
  
SELECT artist FROM playlist;
SELECT count(Artist) from playlist; -- Displays the count of Artist

For average aggregate function:

SELECT AVG(Income) FROM employees;-- it will give the average of income by total number of enployees in employees table.

SELECT AVG(Income) AS "Avg income"
FROM employees
WHERE income > 25000; -- It will display the average income of employees based upon conditon income should be greater than 25000 and display in new column named as Avg income

For MAX aggregate function:

SELECT MAX(Income) AS "Highest income"
FROM employees; -- It will display the highest income in separate column named as Highest income from all the employees in employees table.

For MIN Aggregate function:

SELECT MIN(salary) AS "Lowest Salary"
FROM employees; -- It will display the lowest income in separate column named as lowest income from all the employees in employees table.