Web サイト用のプライベート メッセージング システムを作成しています。ユーザーは、複数の他のユーザー (自分自身を含む) と通信できます。私は3つのテーブルを持っています
- users
- conversation_list
- conversation_messages
以下に示すように、私のデータベースの場合。
users
テーブルはすべてのユーザーを保持します
テーブルにはconversation_messages
書き込まれたメッセージが保持され、各メッセージには conversation_id があります
はconversation_list
、各会話の参加者のリストを保持します
もちろん、各会話は一意のconversation_id
ここで、テーブルから次のクエリを実行したいと思います。
- getInboxMessages <-- Difficult
Get all new messages directed to a user.
Replies to a message should be grouped as a conversation
and the latest reply previewed
- getOutboxMessages
Get all messages sent by the user.
Replies to messages should be grouped as a conversation
and only the latest reply previewed
- getConversation
Each message with all replies
- isUnreadMessage
Check if a message has been read or not
- getNumberOfUnreadMessages
Get the number of unread messages
これまでに行ったことを以下に示します。
getOutboxMessages
、getConversation
、isUnreadMessage
およびgetNumberOfUnreadMessages
機能しますが、クエリは最適ではない可能性があります! を手に入れるのに本当に苦労しgetInboxMessages
ます。
受信トレイで会話の最初のスレッドしか取得できません。他のスレッド (返信) は、新しいメッセージとしてではなく、送信されたメッセージ (送信トレイ) として認識されます。ただし、メッセージへの返信 (会話の一部) は新しいメッセージとして表示されません!
アイデア?getInboxMessages の適切なクエリの取得と、クエリの最適化に関するサポートを心から歓迎します。
CREATE TABLE IF NOT EXISTS `conversation_list` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_id` varchar(50) NOT NULL,
`conversation_id` int(11) NOT NULL,
`added_by` varchar(50) NOT NULL,
`date_created` int(11) NOT NULL,
`date_lastPost` int(11) NOT NULL,
`date_lastView` int(11) NOT NULL,
`status` tinyint(1) NOT NULL,
UNIQUE KEY `id` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE IF NOT EXISTS `conversation_messages` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`sender` varchar(50) DEFAULT NULL,
`conversation_id` int(11) NOT NULL,
`message` text NOT NULL,
`date_created` int(11) NOT NULL,
`status` tinyint(1) NOT NULL,
UNIQUE KEY `id` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE IF NOT EXISTS `users` (
`username` varchar(30) NOT NULL,
`password` varchar(40) default NULL,
`usersalt` varchar(8) NOT NULL,
`userid` varchar(32) default NULL,
`userlevel` tinyint(1) unsigned NOT NULL,
`email` varchar(50) default NULL,
`timestamp` int(11) unsigned NOT NULL,
`regdate` int(11) unsigned NOT NULL,
PRIMARY KEY (`username`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
クエリ
getInboxMessages
================
SELECT *
FROM conversation_messages AS m
JOIN
(SELECT mx.conversation_id,
MAX(mx.date_created) AS MaxTime
FROM conversation_messages AS mx
GROUP BY mx.conversation_id) AS mx ON m.conversation_id = mx.conversation_id
AND m.date_created = mx.MaxTime
JOIN
(SELECT mu.conversation_id
FROM conversation_list AS mu
WHERE mu.user_id = :subuser
GROUP BY mu.conversation_id) AS mux ON m.conversation_id = mux.conversation_id
JOIN conversation_list AS mu ON m.conversation_id = mu.conversation_id
GROUP BY mu.conversation_id
ORDER BY m.date_created DESC
getOuboxMessages
================
SELECT *
FROM conversation_messages AS m
JOIN
(SELECT mx.conversation_id,
MAX(mx.date_created) AS MaxTime
FROM conversation_messages AS mx
GROUP BY mx.conversation_id) AS mx ON m.conversation_id = mx.conversation_id
AND m.date_created = mx.MaxTime
JOIN
(SELECT mu.conversation_id, mu.user_id
FROM conversation_list AS mu
WHERE mu.added_by = :subuser
GROUP BY mu.conversation_id) AS mux ON m.conversation_id = mux.conversation_id
JOIN conversation_list AS mu ON m.conversation_id = mu.conversation_id
ORDER BY m.date_created DESC
isUnreadMessage
===============
SELECT * FROM conversation_list WHERE date_created >= date_lastView AND conversation_id = :messageid AND user_id = :subuser
getConversation
===============
SELECT conversation_id, message, sender, date_created
FROM conversation_messages
WHERE conversation_id = :submessage_id
ORDER BY date_created DESC
getNumberOfUnreadMessages
=========================
SELECT l.conversation_id, count(*)
FROM conversation_list l
JOIN conversation_messages m ON m.conversation_id = l.conversation_id AND m.date_created >= l.date_lastview
WHERE l.user_id = :subuser
GROUP BY l.conversation_id