NHibernate QueryOver 有限制答案

【问题标题】：NHibernate QueryOver with RestrictionsNHibernate QueryOver 有限制
【发布时间】：2014-07-07 03:03:14
【问题描述】：

我是 NHibernate 的新手，正在尝试使用 QueryOver。我有以下 NHibernate 查询

var departments = session
   .QueryOver<Department>()
   .Where(Restrictions.On<Department>x=> x.Parent.Id).IsIn(new List<int> {100}))
   .List().ToList();

我有一个值要传递给 IsIn，为此我必须新建一个列表 (new List<int> {100}))。有没有更清洁的方法？

【问题讨论】：

标签： c# nhibernate linq-to-nhibernate queryover

【解决方案1】：

你的语法没问题，只有很少的更改或改进可以做......他们是：

IList<Department> departments;
var parents = new List<int> {167};

// advantage of this "original" QueryOver is, that it can accept
// more parent IDs.. not only one "100" as in our example
// so if we neet children of 100,101,102
// we can get more from this syntax: new List<int> {100, 101,102...};
departments = session
    .QueryOver<Department>()
    .Where(Restrictions.On<Department>( x=> x.Parent.Id)
        .IsIn(parents))
    .List();

// this style is just a bit more straightforward 
// saving few chars of code, using 'WhereRestrictionOn'
departments = session
    .QueryOver<Department>()
    .WhereRestrictionOn(x => x.Parent.Id).IsIn(parents)
    .List();

// in case we do have the only one parent ID to search for
// we do not have to use the IS IN
departments = session
    .QueryOver<Department>()
    .Where(x => x.Parent.Id == 100)
    .List();

查看更多：16.2. Simple Expressions

【讨论】：