Question

在sql server中，我有一个带有此结构的表（userMessageTbl）

User UserMessage UserMessageDate AdminMessage AdminMessageDate

现在我希望按日期UserMessage从此表中选择AdminMessageDate和DES。

例如

User   UserMessage UserMessageDate AdminMessage AdminMessageDate

test   hi          2015-03-1       thanks       2015-10-4
test   ok          2015-08-2       car          2015-09-1
test   u           2015-10-2       book         2015-10-3

我想得到这个：

thanks
book
u
car
ok
hi

感谢您的帮助

Answer 1

在派生表中执行UNION ALL。然后订购结果。

select msg from
(
select UserMessage as msg, UserMessageDate as msgdate from table
union all
select AdminMessage as msg, AdminMessageDate as msgdate from table
) as dt
order by msgdate

Answer 2

; WITH MD AS
(
    SELECT UserMessage AS [Message], UserMessageDate AS [Date] FROM userMessageTbl
    UNION ALL
    SELECT AdminMessage AS [Message], AdminMessageDate AS [Date] FROM userMessageTbl
)
SELECT [Message], [Date] FROM
MD
ORDER BY [Date] DESC

Answer 3

通过使用Cross Apply，Co-related Subquery和Order by我们也可以实现这个

  Select val from (
    select val,dval from table1
    CROSS APPLY (values ('UserMessage',UserMessage),
                 ('AdminMessage',AdminMessage))cs(col,val)
    CROSS APPLY (values ('UserMessageDate',UserMessageDate),
                 ('AdminMessageDate',AdminMessageDate))vs(dcol,dval)  )T
                 ORDER BY T.dval Desc

从两列日期

3 个答案: