Linq到实体的导航属性

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问题描述

在实体框架中，我有两个表(两个实体):具有一对多关系的人员和角色.在人员表中，我有一个角色导航属性:

//People.cs
public virtual ICollection<Role> Role { get; set; }

现在我想检索所有具有"酒保"角色的人.我怎样才能做到这一点?我想在查询表达式方法中对实体使用 linq.我试过了:

var listPerson = (from p in SiContext.People
                 where p.Role.Name = 'barman'
                 select p).ToList();

问题是我无法创建 p.Ruolo.Name，因为 p.Ruolo 是一个没有属性"Name"的 ICollectionType(而实体 Role 具有该属性)

推荐答案

由于role是一个集合，所以需要使用Any

var listPerson = (from p in SiContext.People
                 where p.Role.Any(x => x.Name == "barman")
                 select p).ToList();

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问题描述

In entity framework i have two table (two entities): People and Role with one to many relationship. In the People tables i have a navigation property to Role:

//People.cs
public virtual ICollection<Role> Role { get; set; }

Now i want retrieve all people that have role as 'barman'. How can i achieve this? I want use linq to entities in the query expression method. I've tried:

var listPerson = (from p in SiContext.People
                 where p.Role.Name = 'barman'
                 select p).ToList();

The problem is that i cannot make p.Ruolo.Name because p.Ruolo is a ICollectionType that doesn't have the property "Name" (while the entity Role has that property)

推荐答案

Since role is a collection, you need to use Any

var listPerson = (from p in SiContext.People
                 where p.Role.Any(x => x.Name == "barman")
                 select p).ToList();

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