How can I run multiple inserts with NHibernate in one go?

问题

I am trying to find the most efficient way of running multiple (> 1000) insert statements with NHibernate.

The actual insert statement is very simple as it uses an FK ID from a newly created object together with values from a subquery. Here's what I would write in SQL:

insert into dbo.NotificationView
select 
    1 AS IDOfNewItem, 
    U.Id AS UserID, 
    0 AS HasEdited
from
    [User] U
    INNER JOIN UserSite US ON U.Id = US.UserId
where
    US.SiteId = 1

I have seen that there is the parameter called adonet.batch_size (NHibernate: insert multiple items at once) that can be set in the "hibernate-configuration" XML file, but it appears that this will simply create the same number of insert statements as there are objects.

Is there a way to run the insert in one go, without iterating through each item?

If so, does this negatively affect the cache in any way?

回答1:

adonet.batch_size works, as long as:

• You are using a supported DB (SQL Server, not sure about Oracle)
• You are using a supported generator (for example, identity doesn't work)
• You don't do anything "strange" with your entities.

Anyway, it looks like you are trying to do a bulk-insert, which is totally unrelated.

You can accomplish that with DML-style operations in HQL.

来源：https://stackoverflow.com/questions/4166590/how-can-i-run-multiple-inserts-with-nhibernate-in-one-go