這個是在國外論壇找到的，這個方法可行

----------------------------Origin SQL-------------------------------
SELECT table1.id, table1.date_added, table2.date_added
FROM table1
LEFT JOIN table2 ON table1.id=table2.id
AND table1.date_added > table2.date_added


----------------------------Modified SQL-------------------------------
SELECT a.id, a.date_added, b.date_added
FROM table1 a
LEFT JOIN
(SELECT table1.id, table2.date_added
FROM table1
JOIN table2 ON table1.id=table2.id
WHERE table1.date_added > table2.date_added) b
ON a.id = b.id