Chapter 7Grouping Data
In this chapter you will learn how to use the GROUP BY and HAVING clauses to group and filter data.
GROUP BY clause — Used with aggregate functions to combine groups of records into a single functional record.
HAVING clause — Used with the GROUP BY clause to set conditions on groups of data calculated from aggregate functions.
The GROUP BY Clause
In Chapter 4 we covered the ORDER BY clause, which affects the results of a query by returning records in either descending or ascending order. In this chapter we will be covering the GROUP BY clause, which is used with aggregate functions to combine groups of records into a single record. We briefly mentioned ...