Learn SQL Database Programming

Learning how to use the GROUP BY clause to group query results using aggregate functions

Using aggregate functions with GROUP BY can give you some interesting summarized results. We learned a bit about this already in Chapter 9, Working with Expressions. There are a couple of ways you can use aggregate functions in a query. One way requires a GROUP BY, while one doesn't.

If you want to summarize an entire table, you don't need to use GROUP BY, as shown in the following query:

USE lahmansbaseballdb; SELECT sum(AB) AS sum_at_batsFROM batting; 

The results from running the previous query can be seen in the following table:

sum_at_bats

'14922240'

The previous result is the sum of all the at-bats (AB) for the entire table. That's ...