在使用继承属性的lambda的Fluent NHibernate映射中应用过滤器? [英] Applying a filter in a Fluent NHibernate mapping using a lambda referencing an inherited property?

问题描述

是否有任何方法可以在流畅的nhibernate映射文件中指定仅将条件有条件地拉入业务实体的方法?

Is there any way to specify in a fluent nhibernate mapping file a way to only conditionally pull values into a business entity?

我当前的映射片段是:

            HasMany(m => m.GroupUsers)
            .Table("GroupUsers")
            .KeyColumns.Add("UserEntityId")
            .Inverse()
            .Cascade.All();

理想情况下，我想要这个(它可以编译但会抛出一个未定义gu的运行时错误):

Ideally, I'd like to have this (which compiles but throws a runtime error that gu isn't defined):

            HasMany(m => m.GroupUsers)
            .Table("GroupUsers")
            .KeyColumns.Add("UserEntityId")
            .Where(gu => gu.DeleteDate == null)
            .Inverse()
            .Cascade.All();

问题的症结在于，我希望映射仅撤回那些删除日期为空的组用户条目.

The crux of the issue is that I'd like the mapping to only pull back those group users entries with a null delete date.

删除日期在基类上

推荐答案

来自FluentNhibernate

From the FluentNhibernate API documentation:

T Where(Expression>哪里)

T Where(Expression> where)

为此一对多关系设置where子句.注意:这个仅支持简单情况，对于更复杂的情况，请使用字符串重载条款.

Sets the where clause for this one-to-many relationship. Note: This only supports simple cases, use the string overload for more complex clauses.

对基类属性的过滤似乎属于复杂"情况.

It seems filtering for base class properties is belongs to the "complex" cases.

因此，您应该使用 Where(String)重载(我尚未测试语法...):

So you should use the Where(String) overload (I haven't tested the syntax...):

HasMany(m => m.GroupUsers)
            .Table("GroupUsers")
            .KeyColumns.Add("UserEntityId")
            .Where("DeleteDate is null")
            .Inverse()
            .Cascade.All();

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