ORM概念的一些问题....你怎么看？ [英] some problems with ORM concept....what do you think?
问题描述
对于我搜索过的所有ORM，我总是发现两个大问题：
1）要更新或删除一组记录，必须先将它带到内存中。
如果你在一个循环中并且必须做n次，那么你必须查询
这个设置n次。如果ORM可以更容易（以
强类型方式）调用动态查询来直接更新/删除
记录，那就太好了。
2）我注意到所有ORM都使用集合作为
查询的返回数据类型。那么，你不能添加，删除，替换或重新排序这个
集合中的元素......这限制了你工作的方式很多，特别是如果你是
在循环中迭代并且必须对同一个表进行更改
迭代...
您对此有何看法？
For all the ORM i have searched around, I have always found two big problems:
1) To update or delete a set of records you must first bring it to memory.
If you are inside a loop and have to do it n times, then you have to query
this set n times as well. Would be nice if ORM could make it easier (in a
strongly type manner) to call a dynamic query to directly update/delete
records.
2) I have noticed all ORM work with collection as thei return datatype of a
query. Well, you cannot add, delete, replace, or reorder the elements in this
collection...this restrict a lot the way you can work, specially if you are
iterating in a loop and have to make changes to the same table you are
iterating...
What are your opinions about it ?
推荐答案
当然，您可以在NHibernate中使用HQL完成所有这些工作。
J.
Bruce One写道：
Sure you can do all of that with HQL in NHibernate.
J.
Bruce One wrote:
对于我搜索过的所有ORM，我总是发现两个大问题：
1）要更新或删除一组记录，首先必须将其带入内存。
如果你在一个循环中并且必须这样做n次，那么你必须查询
这个设定也是n次。如果ORM可以更容易（以
强类型方式）调用动态查询来直接更新/删除
记录，那就太好了。
2）我注意到所有ORM都使用集合作为
查询的返回数据类型。那么，你不能添加，删除，替换或重新排序这个
集合中的元素......这限制了你工作的方式很多，特别是如果你是
在循环中迭代并且必须对同一个表进行更改
迭代...
您对此有何看法？
For all the ORM i have searched around, I have always found two big problems:
1) To update or delete a set of records you must first bring it to memory.
If you are inside a loop and have to do it n times, then you have to query
this set n times as well. Would be nice if ORM could make it easier (in a
strongly type manner) to call a dynamic query to directly update/delete
records.
2) I have noticed all ORM work with collection as thei return datatype of a
query. Well, you cannot add, delete, replace, or reorder the elements in this
collection...this restrict a lot the way you can work, specially if you are
iterating in a loop and have to make changes to the same table you are
iterating...
What are your opinions about it ?
我可能对我真正意义上的内容有所了解。
我的意思是所有ORM都有下面这两个问题...
Hibernate（我已经研究过）以这种方式工作，即
它必须将所有需要更新/删除的记录带入内存，并且，因为
它适用于集合，你只是无法更新/删除这个
集合的任何成员，这样集合就会丢失....
Jimmy写道：
I may have misexposed what I really meant.
I meant all ORM do HAVE these 2 problems below...
Hibernate (which I have already studied) works exaclty this ways, that is,
it has to bring to memory all records it needs to update/delete, and, since
it works with collections, you just cant update/delete any member of this
collection in such a way the collection gets "lost"....
"Jimmy" wrote:
当然你可以在NHibernate中用HQL完成所有这些。
J.
Bruce One写道：
Sure you can do all of that with HQL in NHibernate.
J.
Bruce One wrote:
对于我搜索过的所有ORM，我总是发现两个大问题：
1）要更新或删除一组记录，首先必须将它带到内存中。
如果你在循环中并且必须做n次，那么你必须查询
这套也是n次。如果ORM可以更容易（以
强类型方式）调用动态查询来直接更新/删除
记录，那就太好了。
2）我注意到所有ORM都使用集合作为
查询的返回数据类型。那么，你不能添加，删除，替换或重新排序这个
集合中的元素......这限制了你工作的方式很多，特别是如果你是
在循环中迭代并且必须对同一个表进行更改
迭代...
您对此有何看法？
For all the ORM i have searched around, I have always found two big problems:
1) To update or delete a set of records you must first bring it to memory.
If you are inside a loop and have to do it n times, then you have to query
this set n times as well. Would be nice if ORM could make it easier (in a
strongly type manner) to call a dynamic query to directly update/delete
records.
2) I have noticed all ORM work with collection as thei return datatype of a
query. Well, you cannot add, delete, replace, or reorder the elements in this
collection...this restrict a lot the way you can work, specially if you are
iterating in a loop and have to make changes to the same table you are
iterating...
What are your opinions about it ?
Bruce One< ra ** @ virtualsoftware.com.brwrote：
Bruce One <ra**@virtualsoftware.com.brwrote:
我可能会错误地说出我的意思。
我的意思是所有ORM都有以下这两个问题...
Hibernate（我有）已经研究过了这种方式很有效，也就是说，它必须将所有需要更新/删除的记录带到内存中，并且，因为
它适用于集合，你不能更新/删除这个
集合的任何成员，这样集合就会丢失....
I may have misexposed what I really meant.
I meant all ORM do HAVE these 2 problems below...
Hibernate (which I have already studied) works exaclty this ways, that is,
it has to bring to memory all records it needs to update/delete, and, since
it works with collections, you just cant update/delete any member of this
collection in such a way the collection gets "lost"....
不，Hibernate（至少Java版本）*不必*获取
记录以更新/删除它们。
参见
http：//www.hibernate .org / hib_docs / v3 ... tch.html＃batch
-direct
又名 http://tinyurl.com/4kpug
并向下滚动到DML风格的操作。
-
Jon Skeet - < sk *** @ pobox.com>
< a rel =nofollowhref =http://www.pobox.com/~skeettarget =_ blank> http://www.pobox.com/~skeet 博客： http://www.msmvps.com/jon.skeet
如果回复该组，请不要给我发邮件
No, Hibernate (at least the Java version) does *not* have to fetch
records in order to update/delete them.
See
http://www.hibernate.org/hib_docs/v3...tch.html#batch
-direct
aka http://tinyurl.com/4kpug
and scroll down to "DML-style operations".
--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too
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