Aggregate functions display summaries of the values in specified columns. You can also use the GROUP BY clause, HAVING clause, and ORDER BY clause to group and sort the results of queries using aggregate functions, and the UNION operator to combine the results of queries.
This chapter describes how to group and sort query results.
Summarizing query results using aggregate functions
The GROUP BY clause: organizing query results into groups
Understanding GROUP BY
The HAVING clause: selecting groups of data
The ORDER BY clause: sorting query results
The ROLLUP operation: adding summary information to GROUP BY queries
Performing set operations on query results with UNION, INTERSECT, and EXCEPT
Standards and compatibility