Mysql 合并不同表中的2列

我有两张桌子

1.Message - Sender_Number,SMS,DateTime.
2.Replies - Receiver_Number,SMS,DateTime.

我想合并所有列，并将2个DateTime列合并为一列，然后按时间排序

例如：

Messages Table:
123 | Hello there. | 2012-10-22 3:50
121 | HI I like U..| 2012-10-22 9:10

Replies Table:
123 | how are u... | 2012-10-22 5:50
121 | HI I like U2 | 2012-10-22 9:30

DESIRED OUTPUT (In 1 table):
123 | Hello there. | 2012-10-22 3:50 
123 | how are u... | 2012-10-22 5:50 
121 | HI I like U..| 2012-10-22 9:10 
121 | HI I like U2 | 2012-10-22 9:30 

你需要一个

应该是这样的

SELECT * FROM (
SELECT Sender_Number,SMS,DateTime FROM Messages
UNION 
SELECT Receiver_Number,SMS,DateTime FROM Replies
)
ORDER BY DateTime

另外，我不会调用列

DateTime

，因为它是

MySQL

中的数据类型。这可能会引起问题

SELECT * FROM (
SELECT Sender_Number,SMS,DateTime FROM Messages
UNION 
SELECT Receiver_Number,SMS,DateTime FROM Replies
)
ORDER BY DateTime