How to filter and select a List that is an attribute of a class LINQ?-CodePudding

I have a Privilege

public class Privilege
{
   public virtual string Name { get; set; }
   public virtual ICollection<Role> Roles { get; set; } = new List<Role>();

}

I have a Role which contains a collection of Privilege and a corresponding UserType that the Privilege belongs to.

public class Role
{
    public virtual ICollection<Privilege> Privileges { get; set;} = new List<Privilege>();
    public virtual UserType UserType { get; set;}
}

I am trying to get a List<Privilege> from the privilege repo that only contains Privileges which have the Role I pass. My problem is kind of confusing because both classes have a collection of the other, and this codebase is very spaghetti like and cant be altered.

Here is my attempt, the issue is I cant actually get a List<Privilege> but instead get this crazy IQueryable<IEnumerable<ICollection<Privilege>>> variable back.

_privRepo.Query().Select(p => p.Roles.ToList().Where(r => r.UserType == UserType.Manager).Select(x => x.Privileges);

CodePudding user response：

assuming _privRepo is an entityFramework DbContext, i would say something like this should do the trick :

var privileges = _privRepo.Where(p => p.Roles.Any(r => r.UserType == UserType.Manager)).ToList();

or the async version

var privileges = await _privRepo.Where(p => p.Roles.Any(r => r.UserType == UserType.Manager)).ToListAsync();

CodePudding user response：

You have to refactor your code, if it is a many to many relation then there should be another class to build the relation between them.

https://docs.microsoft.com/en-us/ef/core/modeling/relationships

though you found an workaround of your query.