列表里面的IQueryable对象

考虑以下几点：列表里面的IQueryable对象

public class Person 
{ 
    public int ID { get; set;} 
    public string Name { get; set;} 
    public IQueryable<Pet> Pets { get;set; } 
} 

public class Pet 
{ 
    public int id { get; set; } 
    public int OwnerId { get; set; } 
    public string Name { get; set; } 
} 

public class SearchCriteria 
{ 
    public string PersonName {get; set; } 
    public List<string> PetNames {get; set;} 
}

实现全选的人与他们的宠物，同时用一个IQueryable

public List<Person> GetWithPets(SearchCriteria search) 
{ 
    var people = (from p in context.People 
        where p.Name == search.PersonName 
        select new Person{ 
          ID = p.ID, 
         Name = p.Name, 
         Pets = (from pt in context.Pets 
           where pt.OwnerId == p.ID 
           select new Pet { 
            id = pt.ID, 
           OwnerId = pt.OwnerId, 
           Name = pt.Name 
           }).AsQueryable 
        }).AsQueryable(); 

     foreach(var str in search.PetNames) 
     { 
      people = people.Where(o=>o.Pets.Any(p=>p.Name == str)); 
     } 
    return people.ToList(); 
}

我的问题搜索是，不管在foreach的，其搜索名，在返回人名单，宠物为null即使有那个人，我有没有哪里出了错相关宠物吗？

编辑：

public class Person 
{ 
    public int ID { get; set; } 
    public string Name { get; set; } 
    public IQueryable<Animal> Pets { get; set; } 
} 

public class Animal 
{ 
    public int id { get; set; } 
    public int? OwnerId { get; set; } 
    public string Name { get; set; } 
} 

public class SearchCriteria 
{ 
    public string PersonName { get; set; } 
    public List<string> PetNames { get; set; } 
} 



class Program 
{ 
    public static List<Person> GetWithPets(SearchCriteria search) 
    { 
     using (DatabaseEntities context = new DatabaseEntities()) 
     { 
      var people = (from p in context.Peoples 
          where p.Name == search.PersonName 
          select new Person 
          { 
           ID = p.ID, 
           Name = p.Name, 
           Pets = (from pt in context.Pets 
             where pt.OwnerID == p.ID 
             select new Animal 
             { 
              id = pt.ID, 
              OwnerId = pt.OwnerID, 
              Name = pt.Name 
             }).AsQueryable() 
          }).AsQueryable(); 

      foreach (var str in search.PetNames) 
      { 
       people = people.Where(o => o.Pets.Any(p => p.Name == str)); 
      } 
      return people.ToList(); 
     } 
    }

来源

2012-04-04 Rami Sakr

你有什么方法咋办回来？用'Name'等于'search.PersonName'，并使用具有名称是在'search.PetNames'任何宠物的人的名单？ – Bazzz 2012-04-04 11:02:46

我的方法是应该返回具有名称等于search.PersonName与他们所有的宠物，但只有那些谁拥有与在search.PetNames – 2012-04-04 11:09:21

这些名字的宠物是人的人员名单'Person'和'Pet'实体映射到数据库还是他们只有助手类来获得搜索结果？如果你删除了'foreach'循环会发生什么？ 'Pets'仍然是'null'吗？ – Slauma 2012-04-04 11:35:31

可能你可以尝试这样的事情

var people = (from p in context.People 
        where p.Name == search.PersonName 
        select new Person{ 
          ID = p.ID, 
         Name = p.Name, 
         Pets = (from pt in context.Pets 
           where pt.OwnerId == p.ID 
           select new Pet { 
            id = pt.ID, 
           OwnerId = pt.OwnerId, 
           Name = pt.Name 
           }) 
        }).Include("Pets").AsQueryable();

来源

2012-04-04 11:02:46 Jayanga

或者你可以尝试这样的事情

foreach(var str in search.PetNames) 
     { 
      people.Concat(people.Where(o=>o.Pets.Any(p=>p == str)).Include('Pet')); 
     }

来源

2012-04-04 11:14:13 Jayanga

我的主要问题是在选择，宠物是空... – 2012-04-04 11:15:42

@Jayanga您应该修改而不是添加另一种答案你对方的回答。 – 2012-04-04 15:23:55

添加AsQueryable()到Pets集合：

Pets = (from pt in context.Pets 
     where pt.OwnerId == p.ID 
     select new Pet { 
      id = pt.ID, 
      OwnerId = pt.OwnerId, 
      Name = pt.Name 
     }).AsQuerable()

来源

2012-04-04 11:31:43 RePierre

不行的，我试了一下，无法隐式转换类型“System.Linq.IQueryable ”到“System.Collections.Generic.List ” 这是在我的公共类Person { 公众诠释ID {得到;设置;} public string Name {get;设置;} 列表宠物{获得;设置; }} – 2012-04-04 11:40:27

@RamiSakr，看着我建议用'ToList替换'AsQuerable（）''上Pets'（）''宠物=（选自Pt在context.Pets 其中pt.OwnerId == p.ID错误消息 select new Pet { id = pt.ID， OwnerId = pt.OwnerId， Name = pt.Name }）。ToList（）' – RePierre 2012-04-05 11:23:04

如果Person和Pet是和模型的实体如果Person.Pets是导航属性的Pet实体和如果你想拥有完整的Person实体的所有全Pet实体和引用您的评论...

我的方法应该返回一个名称等于的人列表search.PersonName &他们所有的宠物，但只有那些谁拥有宠物与这些名字在search.PetNames

人...你可以这样做：

public List<Person> GetWithPets(SearchCriteria search) 
{ 
    var people = from p in context.People.Include("Pets") 
       where p.Name == search.PersonName 
        && p.Pets.Any(pt => search.PetNames.Contains(pt.Name)) 
       select p; 

    return people.ToList(); 
}

来源

2012-04-04 11:46:59 Slauma

列表里面的IQueryable对象

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