SQL：第一，我收到消息来自或发送到他们的最新发送的消息和时间

沿10个接触我有一个跟进复杂MySQL的问题，我最近问：Show the ten first contacts that I have recieved message SQL：第一，我收到消息来自或发送到他们的最新发送的消息和时间

现在我知道，这是失去了一些东西，我的最后一个问题是：

我想创建SQL语句表明我已经从他们的最新发送的消息和时间收到消息十个第一次接触。表列为messageId，消息，来自ProfileId，属于ProfileId， timeStamp和表被称为消息。数据库是Mysql，并且是Java语言。但我希望这个发生在一个单一的SQL语句。

什么是缺少的是我想说明我还发来的消息，但它应该与我已经发送到我已经从用户收到邮件进行分组：

我有收到消息或发送到与他们最新发送的消息和时间的十个第一联系人。

有点难理解？好。这样想。上面引用的第一个sql语句仅显示我从中获得的消息。但是如果我发送消息呢？该消息将永远不会显示。

这是我的代码，但我没能赢得成功（看看那里我标记注释）：

"SELECT M2.messageProfileId, profiles.profileMiniature, profiles.firstName, profiles.lastName, profiles.timeFormat, lastMessages.message, lastMessages.timeStamp " + 
      "FROM (" + 
      "  SELECT IF(M1.fromProfileId = ?, M1.toProfileId, M1.fromProfileId) AS messageProfileId, " + 
      "   max(M1.timeStamp) AS lastMessageTime " + 
      "  FROM messages AS M1 " + 
      "  WHERE M1.toProfileId = ? " + 
      "  OR M1.fromProfileId = ? " + 
      "  GROUP BY IF(M1.fromProfileId = ?, M1.toProfileId, M1.fromProfileId) " + 
      "  ORDER BY max(M1.timeStamp) DESC " + 
      "  LIMIT 10 " + 
      "  ) AS M2 " + 
      "INNER JOIN messages AS lastMessages " + 
      "ON  (" + 
      "  lastMessages.timeStamp = M2.lastMessageTime " + 
      "AND lastMessages.fromProfileId = M2.messageProfileId" +//This to be like the if statements above, but how? 
      "  )" + 
      "INNER JOIN profiles " + 
      "ON M2.messageProfileId = profiles.profileId ";

UPDATE：

在上面的代码中所有的问号将被替换AA相同的id，例如27

UPDATE：

你只需要现在解决一行。看看上面的注释行。我不知道如何在where语句中声明if语句？

来源

2011-03-04 einstein

是'messageProfileId'一样'messageId'？ – 2011-03-04 23:30:51

否messageProfileId是与该消息相关的profileId。和profileId是一样的userid，但在这种情况下，我称之为profileId。通过相关我的意思是来自ProfileId或toProfileId，取决于我是否收到消息或者如果我发送了消息 – einstein 2011-03-04 23:35:32

messageId是消息的主键就像只是索引 – einstein 2011-03-04 23:40:07

好理解了它自己

"SELECT M2.messageProfileId, profiles.profileMiniature, profiles.firstName, profiles.lastName, profiles.timeFormat, lastMessages.message, lastMessages.timeStamp " + 
       "FROM (" + 
       "  SELECT IF(M1.fromProfileId = ?, M1.toProfileId, M1.fromProfileId) AS messageProfileId, " + 
       "   max(M1.timeStamp) AS lastMessageTime " + 
       "  FROM messages AS M1 " + 
       "  WHERE (M1.toProfileId = ? " + 
       "  OR M1.fromProfileId = ?) " + 
       "  GROUP BY IF(M1.fromProfileId = ?, M1.toProfileId, M1.fromProfileId) " + 
       "  ORDER BY max(M1.timeStamp) DESC " + 
       "  LIMIT 10 " + 
       "  ) AS M2 " + 
       "INNER JOIN messages AS lastMessages " + 
       "ON  (" + 
       "  lastMessages.timeStamp = M2.lastMessageTime " + 
       "AND (" + 
       "  lastMessages.fromProfileId = M2.messageProfileId " + 
       "OR  lastMessages.toProfileId = M2.messageProfileId " + 
       "  )" + 
       "  )" + 
       "INNER JOIN profiles " + 
       "ON M2.messageProfileId = profiles.profileId ";

来源

2011-03-05 00:12:13 einstein

SQL：第一，我收到消息来自或发送到他们的最新发送的消息和时间

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