UC知道帮忙简化一句查询语句吧?对高手来说很简单的！谢谢
来源：百度知道 编辑：UC知道 时间：2024/06/22 15:48:00
SELECT top 1 * from News order by id union select top 1 * from Scenes order by id union select top 1 * from Links order by id union select top 1 * from Amenity order by id
要查到每个表的最后一行,也就是将每个数据表的最后一项提出合并成一个数据集rs，然后调用。
SELECT top 1 * from News order by id desc union select * from( select top 1 * from Scenes order by id desc) union select * from( select top 1 * from Links order by id desc) union select * from( select top 1 * from Amenity order by id desc)
是这样吗？
如果是怎么简化一下啊，太长了
要查到每个表的最后一行,也就是将每个数据表的最后一项提出合并成一个数据集rs，然后调用。
SELECT top 1 * from News order by id desc union select * from( select top 1 * from Scenes order by id desc) union select * from( select top 1 * from Links order by id desc) union select * from( select top 1 * from Amenity order by id desc)
是这样吗？
如果是怎么简化一下啊，太长了
你用的是union，已经剔除重复记录，简化也只能吧order by 去掉，只保留数据结果最多的那张表上的order
将前面的order by id去掉，只保留一个。
SELECT top 1 * from News order union select top 1 * from Scenes union select top 1 * from Links union select top 1 * from Amenity order by id desc
查询结果不包含重复值；
SELECT top 1 * from News order union all select top 1 * from Scenes union all select top 1 * from Links union all select top 1 * from Amenity order by id desc
查询所有值，包括重复值