Question

I am merging two tables, each one with different events data. Each table has a date for the events.

How do I combine these events to sort them seamlessly by date?

SELECT 
   t1.eventName, 
   t1.eventTime, 
   t2.evntName, 
   t2.evntTime
FROM t1
LEFT JOIN t2 ON (t1.eventID = t2.eventID)
ORDER BY ??? DESC
LIMIT 10

Answer 1

@Gonzalo is close but not quite there. You need to put each table into subqueries and alias each column you want in the final result. If one table doesn’t have a column that you need from another use a literal and alias it.

(SELECT eventName, eventTime, foo FROM t1)
UNION ALL
(SELECT evntName AS eventName, evntTime AS eventTime, NULL AS foo FROM t2)
ORDER BY eventTime DESC

Put any WHERE clauses inside the subqueries.