Question

1. What is one example where you would use grouping to summarize data
2. In this example, if you have any filtering criteria would you use the "Where" clause or the "Having" clause and why?

Answer 1

We are using having class to filter grouping data.

The HAVING clause is then applied to the rows in the result set. Only the groups that meet the HAVING conditions appear in the query output. You can apply a HAVING clause only to columns that also appear in the GROUP BY clause or in an aggregate function.

Example ;

SELECT titles.pub_id, AVG(titles.price)  
FROM titles INNER JOIN publishers
ON titles.pub_id = publishers.pub_id  
GROUP BY titles.pub_id  
HAVING publishers.state = 'CA';

If you have any doubts ask me