鉴于以下情况:
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;}
}
在使用 IQueryable 进行搜索时,实现对所有人及其宠物的选择
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();
}
我的问题是,无论搜索名称的 foreach 是什么,在返回的人员列表中,宠物为空,即使有 与那个人有关的宠物,我哪里做错了?
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();
}
}
最佳答案
如果 Person
和Pet
是您的模型的实体并且如果 Person.Pets
是 Pet
实体的导航属性,如果您希望拥有完整的 Person
实体以及所有完整的 Pet
实体并引用您的评论...
my method is supposed to return a list of people that have name equals search.PersonName & ALL their pets but only those people who own the pets with those names in the search.PetNames
...你可以使用这个:
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();
}
关于c# - 列出内部 IQueryable 对象,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/10009681/