NHibernate 中的 List vs Set vs Bag [英] List vs Set vs Bag in NHibernate

问题描述

NHibernate 映射文件中的 list、set 和 bag 有什么区别?每个与 .NET 集合有何关系?

What's the difference between a list, set and bag in the NHibernate mapping file? How does each relate to the .NET collections?

推荐答案

NHibernate 语义:

NHibernate semantics:

1. List:实体的有序集合，允许重复.在代码中使用 .NET IList.索引列需要在 NHibernate 中进行映射.

1. List: Ordered collection of entities, duplicate allowed. Use a .NET IList in code. The index column will need to be mapped in NHibernate.

Set:唯一实体的无序集合，不允许重复.在代码中使用 Iesi.Collection.ISet(NH v4 之前)或 System.Collections.Generic.ISet (NH v4+).重要的是要覆盖GetHashCode 和Equals 以指示重复的业务定义.可以通过定义 orderby 或通过定义导致 SortedSet 结果的比较器进行排序.

Set: Unordered collection of unique entities, duplicates not allowed. Use Iesi.Collection.ISet in code (NH prior to v4) or System.Collections.Generic.ISet (NH v4+). It is important to override GetHashCode and Equals to indicate the business definition of duplicate. Can be sorted by defining an orderby or by defining a comparer resulting in a SortedSet result.

Bag:实体的无序列表，允许重复.在代码中使用 .NET ICollection.该列表的索引列未映射，NHibernate 不支持该列.

Bag: Unordered list of entities, duplicates allowed. Use a .NET ICollection<T> in code. The index column of the list is not mapped and not honored by NHibernate.

这篇关于NHibernate 中的 List vs Set vs Bag的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！