ASP.Net – C# – SQL Server – 只刷新缓存的DataTable,只记录

或者,我建议使用SqlCacheDependency类,它可以为您保持最新的缓存.我不能评论任何现实世界的优点,或性能比较与时间戳方法,因为我自己没有使用它.

还有一篇关于SqlCacheDependency here的有用文章

更新：
是的,我认为它不会真正刷新数据.听起来你必须自己做.
从第二个链接：

When the data changes—and only
then—the cache items based on that
data are invalidated and removed from
the cache. The next time you request
that item from the cache,if it is not
in the cache,you can re-add the
updated version to the cache and be
assured that you have the latest data

第二个链接中还有SQL 2005特定的实现说明：

SQL Server 2005 monitors changes to
the result set of a particular SQL
command. If a change occurs in the
database that would modify the results
set of that command,the dependency
causes the cached item to be
invalidated. This allows SQL Server
2005 to provide row-level
notification.

我个人认为我会采用时间戳方法(这是我以前做过的),因为我无法从中看到SqlCacheDependency会带来任何性能上的好处 – 我认为它会降低性能(只是更容易)实行).有一天,我会试着尝试使用SqlCacheDependency进行正确的性能分析:)

更新2：
关于将新数据合并到现有数据表中,我认为数据表的Merge方法是您想要的.

The Merge method is used to merge two DataTable objects that have largely similar schemas. A merge is typically used on a client application to incorporate the latest changes from a data source into an existing DataTable.
…
…
When merging a new source DataTable into the target,any source rows with a DataRowState value of Unchanged,Modified,or Deleted,is matched to target rows with the same primary key values. Source rows with a DataRowState value of Added are matched to new target rows with the same primary key values as the new source rows.

您只需确保在数据表上定义作为主键的列.