如何按MySQL中不同表的两个日期字段之间的最新更新日期排序

Question

I have two tables CUSTOMERS and QUERIES.. I want to display the result such that if new customer is added to CUSTOMER table or new query is added to QUERY table then which one is added recently among them should be ordered first.. I have tried query like this,

SELECT c.name, q.query FROM CUSTOMER c, QUERY q 
WHERE c.id=q.cust_id 
ORDER BY c.added_date DESC, q.added_date DESC;

But it is not showing proper result.. Plz help..

Answer 1

It should be the following:

order by greatest(c.added_date,q.added_date) desc

This works in postgres and other DBMSs - hopefully works the same for mysql and oracle.