[英]MySql query for selecting latest message from the conversation and messages table join
[英]MySQL - Conversation History overview - Selecting multiple latest items from table
我很高兴通过用PHP构建一个自定义的消息传递系统(使用API来发送和接收消息)来重新创建电话。 我正在尝试在其桌面站点的Facebook消息传递中模拟其功能。
[Col 1] [Col 2]
A list of the Conversation View.
latest messages
received in order
of Newest to oldest
我目前在MySQL中有一个具有以下结构的表:
CREATE TABLE IF NOT EXISTS `History` (
`ID` int(10) NOT NULL AUTO_INCREMENT COMMENT 'MessageID',
`Sender` varchar(10) NOT NULL,
`Recipient` varchar(10) NOT NULL,
`ExtReference` int(20) DEFAULT NULL,
`Date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`Status` varchar(100) NOT NULL,
`userid` int(3) NOT NULL,
`Message` longtext NOT NULL,
PRIMARY KEY (`ID`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=609 ;
日期示例设置为:
INSERT INTO `History` (`ID`, `Sender`, `Recipient`, `ExtReference`, `Date`, `Status`, `userid`, `Message`) VALUES
(1, '0412345678', '0468888888', 33845909, '2013-03-17 04:17:34', '1', 11, 'Just testing....'),
(2, '0412345678', '0400222333', 33845910, '2013-03-17 04:17:35', '1', 11, 'Amazing'),
(3, '0412345678', '0411111111', 33847419, '2013-03-17 04:46:04', '1', 8, 'Nothing here to see'),
(4, '0412345678', '0400222333', 33850155, '2013-03-17 06:31:57', '1', 12, 'Hello there Mr IT Guru :-)'),
(5, '0400222333', '0412345678', 33850179, '2013-03-17 06:33:21', '1', 12, '[Write message here]'),
(6, '0412345678', '0411111111', 33955423, '2013-03-23 01:26:22', '1', 8, 'Hello Charles'),
(7, '0412345678', '0411111111', 33959071, '2013-03-23 03:08:26', '1', 13, 'Sample Message'),
(8, '0400222333', '0412345678', 33964111, '2013-03-23 05:27:51', '1', 13, 'How do I use this system?'),
(9, '0400222333', '0412345678', 34107503, '2013-03-30 03:13:38', '1', 12, 'Is this thing on?'),
(10, '0412345678', '0401411210', 34230869, '2013-03-05 00:18:09', '1', 16, 'Hello')
(在此示例中,我的电话是:0412345678)。 SQL小提琴在这里: http ://sqlfiddle.com/#!2/29197/1/0
我已经解决了如何获取发件人和收件人列中使用的所有唯一编号的列表:
SELECT DISTINCT `Sender` AS phoneID FROM `History`
UNION
SELECT DISTINCT `Recipient` AS phoneID FROM `History`
但是我无法处理如何将最新的日期和消息附加到此数据。
如果我只关注发给我的消息或我发给我的消息,那么可以通过以下两种方式获得帮助:
SELECT `ID`, `Sender`, `Recipient`, MAX(`Date`), `Message` FROM History
GROUP BY Sender
ORDER BY `History`.`Date` DESC
要么
SELECT `ID`, `Sender`, `Recipient`, MAX(`Date`), `Message`, `Status` FROM History
GROUP BY Recipient
ORDER BY `History`.`Date` DESC
有什么想法吗? 如果需要,我可以重新创建“历史记录”表布局。
稍后,我还需要尝试将电话号码和人名一起加入“联系人”表中。
谢谢查理
可能不是最好的方法,但是您可以将两个查询结合起来。 就像是:
SELECT `ID`, `Sender`, `Recipient`,`Date`,`Message`,`Status` FROM
(
SELECT `ID`, `Sender`, `Recipient`, `Date`, `Message`,`Status` FROM History
WHERE Sender = "0412345678"
GROUP BY Sender
UNION
SELECT `ID`, `Sender`, `Recipient`, MAX(`Date`), `Message`, `Status` FROM History
WHERE Recipient = "0412345678"
GROUP BY Recipient
) res
GROUP BY res.ID
ORDER BY res.Date DESC
请注意,这是一个特定的数字。 如果不需要,您可以删除WHERE
子句。
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