私は "チャット" SQLテーブルを読むのに少し助けが必要です。SQL SELECT - Chats
コラム:...取得する方法
Chat_ID - decimal(18, 0) primary key, inflexible-yes
Sent_ID - decimal(18, 0)
Receive_ID - decimal(18, 0)
Time - datetime
Message - nvarchar(MAX)
Sent_ID| Receive_ID | Time | Message
-------+----------+------------------+-----------------
1 | 2 | 11/21/2015 10:00 | Hey! test
-------+----------+------------------+-----------------
2 | 1 | 11/21/2015 10:50 | Hi! respond
-------+----------+------------------+-----------------
1 | 2 | 11/21/2015 10:51 | respond 3
-------+----------+------------------+-----------------
2 | 1 | 11/21/2015 11:05 | respond final
-------+----------+------------------+-----------------
1 | 3 | 11/21/2015 11:51 | Message 1
-------+----------+------------------+-----------------
3 | 1 | 11/21/2015 12:05 | Message 2
-------+----------+------------------+-----------------
1 | 3 | 11/21/2015 12:16 | Message Final
-------+----------+------------------+-----------------
4 | 1 | 11/21/2015 12:25 | New message 1
-------+----------+------------------+-----------------
Sent_ID| Receive_ID | Time | Message
-------+----------+------------------+-----------------
2 | 1 | 11/21/2015 11:05 | respond final
-------+----------+------------------+-----------------
1 | 3 | 11/21/2015 12:16 | Message Final
-------+----------+------------------+-----------------
4 | 1 | 11/21/2015 12:25 | New message 1
-------+----------+------------------+-----------------
あなたは、私が何か必要なことに注意してください(各ユーザに最後のメッセージを?):、MAX(時間) Sent_ID = 1 ..... Receive_ID = 1を簡略化するために、
:WHERE(Sent_ID = @ Receive_ID = @ Sent_IDまたは@ Receive_ID) = 1) は....
を試してみてください? –