使用包含实体框架核心 3.1 时如何过滤嵌套对象

Question

I have a user table that contains a nested table named UserPriviliges in this table I have isDeleted field to identify deleted data without actually deleting it, I want to retrieve a user with its privilege using include

 public async Task<User> GetUser(Guid userId)
    {
        return await RepositoryContext.Users
            .Include(x => x.UserPrivileges).ThenInclude(x => x.Privilege)
            .FirstOrDefaultAsync(x => x.Id == userId);
    }

how to filter UserPriviliges to bring only items with false isDeleted property

in EF Core <3.0 I could do it like this

 return await RepositoryContext.Users
            .Include(x => x.UserPrivileges.Where(y=>y.IsDeleted)).ThenInclude(x => x.Privilege)
            .FirstOrDefaultAsync(x => x.Id == userId);

but its not working any more in EF Core 3.1 it returns

Lambda expression used inside Include is not valid

Answer 1

I don't remember this working in EF Core at all; and usually we would separate this into two queries: 1- fetch the user data, 2- fetch the filtered user privileges

var user = await RepositoryContext.Users
    .FirstOrDefaultAsync(u => u.Id == userId);

await RepositoryContext.UserPrivileges
    .Where(up => up.UserId == userId && !up.IsDeleted)
    .Include(up => up.Privilege)
    .ToListAsync();

return user;

When we bring related data into the context with the 2nd query, ef will take care of populating user.UserPrivileges, so we don't need to assign it at all. This works well if we fetch multiple user data.

Answer 2

One option is :

public async Task<User> GetUser(Guid userId)
{
    return await RepositoryContext.Users
        .Include(x => x.UserPrivileges).ThenInclude(x => x.Privilege)
        .Where(x => x.UserPrivileges.Any(p => p.IsDeleted)) 
        .FirstOrDefaultAsync(x => x.Id == userId);
}

But this will return user with all the UserPrivileges (meaning returned User object will contain both IsDeleted and !IsDeleted UserPrivileges ).

if you have User reference in UserPrivileges, then another option is navigate from UserPrivileges something like below:

RepositoryContext.UserPrivileges
        .Include(x => x.User)
        .Where(x => x.IsDeleted && x.User.Id == userId)