NHibernate标准 - 如何过滤属性的组合 [英] NHibernate Criteria - How to filter on combination of properties

问题描述

我需要使用两个属性的组合过滤一个结果列表。一个简单的SQL语句将如下所示：

I needed to filter a list of results using the combination of two properties. A plain SQL statement would look like this:

SELECT TOP 10 *
FROM Person
WHERE FirstName + ' ' + LastName LIKE '%' + @Term + '%'

我在NHibernate中的ICriteria最终使用的是：

The ICriteria in NHibernate that I ended up using was:

ICriteria criteria = Session.CreateCriteria(typeof(Person));
criteria.Add(Expression.Sql(
    "FirstName + ' ' + LastName LIKE ?",
    "%" + term + "%",
    NHibernateUtil.String));
criteria.SetMaxResults(10);

它工作得很好，但我不知道是否是理想的解决方案，因为我还在了解NHibernate的Criteria API。什么是推荐的替代方案？

It works perfectly, but I'm not sure if it is the ideal solution since I'm still learning about NHibernate's Criteria API. What are the recommended alternatives?

• 除了 Expression.Sql 执行相同的操作？我试过 Expression.Like ，但无法弄清楚如何组合名字和姓氏。


• 我应该映射一个FullName属性到映射类中的FirstName ++ LastName公式？


• 我应该在域对象上创建一个只读FullName属性，然后将其映射到列吗？

• Is there something besides Expression.Sql that would perform the same operation? I tried Expression.Like but couldn't figure out how to combine the first and last names.
• Should I map a FullName property to the formula "FirstName + ' ' + LastName" in the mapping class?
• Should I create a read only FullName property on the domain object then map it to a column?

推荐答案

您可以执行以下操作之一：

You can do one of the following:

• 如果您始终使用全名，最好是拥有一个属性


• 为此创建一个仅限查询的属性（请参阅 http://ayende.com/Blog/archive /2009/06/10/nhibernate-ndash-query-only-properties.aspx ）


• 在HQL中执行查询，更适合自由格式查询（它可能与您的SQL几乎相同）


• 使用适当的基于实体的条件：






---




• If you always work with the full name, it's probably best to have a single property
• Create a query-only property for that purpose (see http://ayende.com/Blog/archive/2009/06/10/nhibernate-ndash-query-only-properties.aspx)
• Do the query in HQL, which is better suited for free-form queries (it will probably be almost the same as your SQL)
• Use a proper entity-based Criteria:

Session.CreateCriteria<Person>()
       .Add(Restrictions.Like(
            Projections.SqlFunction("concat",
                                    NHibernateUtil.String,
                                    Projections.Property("FirstName"),
                                    Projections.Constant(" "),
                                    Projections.Property("LastName")),
            term,
            MatchMode.Anywhere))

这篇关于NHibernate标准 - 如何过滤属性的组合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！