这个：相同数据只取一个的视图如何生成

Question

select
a.BoardId,b.TopicId,a.BoardName,b.Title,b.Content
from TblBoard a,TblTopic b
where a.BoardId=b.BoardId
and b.TopicId=(select max(TopicId) from TblTopic where BoardId=a.BoardId)

Answer 1

小弟拙见,不知道这样行不行
select a.boardid,b.topicid,a.BoardName,b.Title,b.Content
     from table1 a,(select max(title) title
                      from table2 where a.boardid = table2.boradid) b

Answer 2

不好意思写错了:select a.boardid,b.topicid,a.BoardName,b.Title,b.Content
     from table1 a,(select max(topicid) topicid
                      from table2 where a.boardid = table2.boradid) b

Answer 3

楼上的不行，一楼正确
也可以：select
a.BoardId,b.TopicId,a.BoardName,b.Title,b.Content
from TblBoard a,TblTopic b,(select BoardId,max(TopicId) as TopicId from TblTopic group by BoardId)c 
where a.BoardId=b.BoardId
and a.BoardId=c.BoardId
and b.TopicId=c.TopicId

Answer 4

我也弄了一个，请指教
CREATE VIEW ViewLasTopic AS
    SELECT TblBoard.BoardId,TblTopic.TopicId,TblBoard.BoardName,
TblTopic.Title,TblTopic.Content    
    FROM from TblBoard,TblTopic
    WHERE TblBoard.BoardId=TblTopic.BoardId and TblTopic.TopicId=(select max(TopicId) from TblTopic where BoardId=TblBoard.BoardId)

Answer 5

create view ppViewASselect b.boardID,b.TopicID,b.title,a.BoardName,b.Contentfrom (select * from TblTopic a where TopicID=
(select max(topID) from TblTopic where BoardID=A.BoardID))bleft join TblBoard a on b.BoardId=a.BoardId