【发布时间】:2011-12-10 21:51:30
【问题描述】:
我有“GetConversationPaged”sp,它从名为“user_messages_index”的表中选择分页数据,并在名为“social_user_messages”的表中的对话中包含“lastmesage”。 我不确定它是否可以微调,但它可以在缺少一件事的情况下工作。我想按我通过 select MAX(messageId) 获得的 lastMessageId 对“Row_number”进行排序。
PS:我有消息索引和消息表,因为我希望人们将相同的消息发送给多个收件人。我使用索引表而不是一遍又一遍地插入相同的消息
那么,如何按最新消息 ID 对结果进行排序?
这是我正在使用的表格和sps
--索引表--
CREATE TABLE [dbo].[social_user_messages_index](
[senderId] [int] NOT NULL,
[recipientId] [int] NOT NULL,
[messageId] [int] NOT NULL,
[isRead] [bit] NOT NULL
) ON [PRIMARY]
--消息表--
CREATE TABLE [dbo].[social_user_messages](
[id] [int] IDENTITY(1,1) NOT NULL,
[message] [nvarchar](1000) NOT NULL,
[sendDate] [datetime] NOT NULL,
) ON [PRIMARY]
--sp--
ALTER PROCEDURE [dbo].[GetConversationPaged]
@userId int,
@isRead bit,
@PageNumber int,
@PageSize int
AS
BEGIN
DECLARE @FirstRow INT, @LastRow INT, @RowCount INT, @PageCount INT
--- find recordcount and pages
SELECT @RowCount = COUNT(1) OVER(),
@PageCount = COUNT(*) OVER() / @PageSize
FROM social_user_mesages_index s
WHERE s.recipientId = @userId and s.isRead=@isRead
GROUP BY senderId
--- calculate pages
IF @RowCount % @PageSize != 0 SET @PageCount = @PageCount + 1
IF @PageNumber < 1 SET @PageNumber = 1
IF @PageNumber > @PageCount SET @PageNumber = @PageCount
--- select paging data
SELECT currentpage = @PageNumber, totalpages = @PageCount, totalrows = @RowCount
SET @FirstRow = ( @PageNumber - 1 ) * @PageSize + 1;
SET @LastRow = ( @PageNumber - 1 ) * @PageSize + @PageSize;
--- select records
WITH mytable
AS (
SELECT Row_number() OVER (ORDER BY (SELECT 1)) AS rownumber,
(Select name from domains_users d where d.id=s.senderId) as senderName,
(select MAX(messageId)) as lastMessageId,
(select m.[message] from social_user_messages m where m.id = (select MAX(messageId))) as [message]
--,(select m.sendDate from social_user_messages m where m.id = (select MAX(messageId))) as lastMessageDate
,senderId
FROM social_user_mesages_index s
WHERE s.recipientId = @userId and s.isRead=@isRead
GROUP BY senderId
)
SELECT *
FROM mytable
WHERE rownumber BETWEEN @FirstRow AND @LastRow
ORDER BY rownumber ASC;
END
【问题讨论】:
-
好吧,“Row_number() OVER (ORDER BY MAX(messageId) desc) AS rownumber”似乎有帮助。但这对我的大脑来说变得越来越复杂:) 有人可以确认吗?
标签: sql sql-server sql-server-2008 pagination