SQLITE查询以连接两个具有不同条件的相同表

Question

我有一个名为 messages 的 SQL 表，其详细信息如下；

id, sender, recipient, message, timestamp

"1","10204456572654160","10208819391147662","Hi.. : What are you up to?","1459541723279"
"2","10204456572654160","10208819391147662","Got my test message?","1459541749818"
"3","10208819391147662","10204456572654160","This is my message","1459611679108"
"4","10208819391147662","10204456572654160","And another message","1459611735455"
"5","10204456572654160","10208819391147662","And I reply like this","1459611758570"
"6","10153775515332771","10208819391147662","It's me.. Syco !!","1459611900348"
"7","10153775515332771","10208819391147662","You there?","1459611900350"
"8","10208819391147662","10153775515332771","Yes.. What's upp..","1459611900380"
"9","10204464403169266","10208819391147662","How're you doin?","1459612000666"

现在，我想将一个值传递给我的函数 e.g. 10208819391147662 并显示如下列的结果；

1. sender/recipient 的唯一值 NOT 10208819391147662
2. sender/recipient 之间的最后一个 message 是 NOT 10208819391147662 AND sender/recipient 是 10208819391147662。
3. 第二个（消息）的timestamp。

为了实现以下，我有这个sql；

SELECT s1.*, max(c2.message), max(c2.timestamp)
FROM (
    SELECT sender as username 
    FROM messages
    WHERE sender <> '10208819391147662'
    UNION
    SELECT recipient as username 
    FROM messages
    WHERE recipient <> '10208819391147662'
) s1
LEFT JOIN messages c2 ON (s1.username = c2.sender OR s1.username = c2.recipient)
GROUP BY s1.username

我已经使用UNION 成功提取了1st column。但是使用MAX 和Group by 子句在第2 次和第3 次没有运气。

我的最终预期结果应该是；

username, message, timestamp

"10204456572654160","And I reply like this","1459611758570"
"10153775515332771","Yes.. What's upp..","1459611900380"
"10204464403169266","How're you doin?","1459612000666"

到目前为止，这是我的SQLFiddle。任何建议表示赞赏。

Answer 1

其实，最后这是我完成我想要的最终 SQL。

SELECT c2.id, s1.username, c2.message, max(c2.timestamp)
FROM (
    SELECT sender as username 
    FROM messages
    WHERE sender <> '10208819391147662'
    UNION
    SELECT recipient as username 
    FROM messages
    WHERE recipient <> '10208819391147662'
) s1
LEFT JOIN messages c2 ON (s1.username = c2.sender OR s1.username = c2.recipient)
GROUP BY s1.username
ORDER BY timestamp DESC

但不知何故，在SQLFiddle 中，这在MYSQL 中无法按预期工作，但在SQLITE 中运行良好。