sqlmax()函数用法

SELECT MAX(salary) as "Highest salary"
FROM employees;

SELECT department, MAX(salary) as "Highest salary"
FROM employees
GROUP BY department;

USER_NAME，report_job_id，REPORT_NAME，report_run_date。

SELECT report_name, max(report_run_date)
FROM report_history
GROUP BY report_name

SELECT rh.user_name, rh.report_name, rh.report_run_date
FROM report_history rh,
(SELECT max(report_run_date) as maxdate, report_name
FROM report_history
GROUP BY report_name) maxresults
WHERE rh.report_name = maxresults.report_name
AND rh.report_run_date= maxresults.maxdate;

Let's take a few moments to explain what we've done.

(SELECT max(report_run_date) as maxdate, report_name
FROM report_history
GROUP BY report_name) maxresults