通用存储库筛选器子属性

Question

I am using a generic repository to query my database here . All my entities inherit a base class which has a property Active , I set Active to false when the user deletes it. The problem I am facing now is that while the code below works fine for main entity I could not figure out how to return only Active child activities.

I have tried using dynamic linq but not successfully. Is there any way to do this except the most obvious using linq on child entities?

 public virtual TEntity GetById(object id,
        Expression<Func<TEntity, bool>> filter = null,
        string includeProperties = "")
    {
        IQueryable<TEntity> query = DbSet;

        if (filter != null)
        {
            query = query.Where(filter);
        }
        if (includeProperties.Length > 0)
        {
            query = includeProperties.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
                .Aggregate(query, (current, includeProperty) => current.Include(includeProperty));
        }
        else
        {
            return DbSet.Find(id);
        }

        if (query.Any())
        {
            return query.First();
        }
        return query.First();
    }

Answer 1

You should create filter for that ( EntityFramework.Filters ):

public interface IActive
{
    public bool Active {get;set;}
}

public class MyClass : IActive
{
    public int Id {get;set;}
    public bool Active {get;set;}
}

protected override void OnModelCreating(DbModelBuilder modelBuilder) 
{   
    modelBuilder.Conventions
       .Add(FilterConvention.Create<IActive, bool>("MyFilter", (entity, Active) => entity.Active);
}

Usage:

var filter = context.EnableFilter("MyFilter");
filter.SetParameter("Active", true);

var item = GetById(1);
//now inside GetById method 'item' and all it's children will be filtered with "Active == true" condition

context.DisableFilter("MyFilter");

Answer 2

One of options :

public virtual TEntity GetById(object id,
        Expression<Func<TEntity, bool>> filter = null,
        string includeProperties = "")
    {
        IQueryable<TEntity> query = GetActive();

        if (filter != null)
        {
            query = query.Where(filter);
        }
        if (includeProperties.Length > 0)
        {
            query = includeProperties.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
                .Aggregate(query, (current, includeProperty) => current.Include(includeProperty));
        }
        else
        {
            return DbSet.Find(id);
        }

        if (query.Any())
        {
            return query.First();
        }
        return query.First();
    }

public virtual IQueryable<TEntity> GetActive()
{
    return 
        DbSet.Where(a => a.Active);
}