列表裏面的IQueryable對象

考慮以下幾點：列表裏面的IQueryable對象

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;} 
}

實現全選的人與他們的寵物，同時用一個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(); 
}

我的問題搜索是，不管在foreach的，其搜索名，在返回人名單，寵物爲null即使有那個人，我有沒有哪裏出了錯相關寵物嗎？

編輯：

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(); 
     } 
    }

來源

2012-04-04 Rami Sakr

你有什麼方法咋辦回來？用'Name'等於'search.PersonName'，並使用具有名稱是在'search.PetNames'任何寵物的人的名單？ – Bazzz 2012-04-04 11:02:46

我的方法是應該返回具有名稱等於search.PersonName與他們所有的寵物，但只有那些誰擁有與在search.PetNames – 2012-04-04 11:09:21

這些名字的寵物是人的人員名單'Person'和'Pet'實體映射到數據庫還是他們只有助手類來獲得搜索結果？如果你刪除了'foreach'循環會發生什麼？ 'Pets'仍然是'null'嗎？ – Slauma 2012-04-04 11:35:31

可能你可以嘗試這樣的事情

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();

來源

2012-04-04 11:02:46 Jayanga

或者你可以嘗試這樣的事情

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

來源

2012-04-04 11:14:13 Jayanga

我的主要問題是在選擇，寵物是空... – 2012-04-04 11:15:42

@Jayanga您應該修改而不是添加另一種答案你對方的回答。 – 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()

來源

2012-04-04 11:31:43 RePierre

不行的，我試了一下，無法隱式轉換類型「System.Linq.IQueryable 」到「System.Collections.Generic.List 」這是在我的公共類Person { 公衆詮釋ID {得到;設置;} public string Name {get;設置;} 列表寵物{獲得;設置; }} – 2012-04-04 11:40:27

@RamiSakr，看着我建議用'ToList替換'AsQuerable（）''上Pets'（）''寵物=（選自Pt在context.Pets 其中pt.OwnerId == p.ID錯誤消息 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是和模型的實體如果Person.Pets是導航屬性的Pet實體和如果你想擁有完整的Person實體的所有全Pet實體和引用您的評論...

我的方法應該返回一個名稱等於的人列表search.PersonName &他們所有的寵物，但只有那些誰擁有寵物與這些名字在search.PetNames

人...你可以這樣做：

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(); 
}

來源

2012-04-04 11:46:59 Slauma

列表裏面的IQueryable對象

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