EF Core: Soft delete with shadow properties and query filters

Question

I\'ve created an interface to try to do a soft delete, mixing shadow properties and query filters. But it\'s not working.

public interface IDeletableEntity {         


        

Answer 1

That does not work for me, .net core 3.1, so I tried the following approach which is kinda similar :

// fetch entity types by reflection then: 

 softDeletedEntityTypes.ForEach(entityType =>
            {
                modelBuilder.Entity(entityType, builder =>
                {
                    builder.Property("IsDeleted");
                    builder.HasQueryFilter(GenerateQueryFilterExpression(entityType));
                });
            });


 private static LambdaExpression GenerateQueryFilterExpression(Type entityType)
        {            
             // the following lambda expression should be generated
             // e => !EF.Property(e, "IsDeleted")); 

            var parameter = Expression.Parameter(entityType, "e"); // e =>

            var fieldName = Expression.Constant("IsDeleted", typeof(string)); // "IsDeleted"

            // EF.Property(e, "IsDeleted")
            var genericMethodCall = Expression.Call(typeof(EF), "Property", new[] {typeof(bool)}, parameter, fieldName);

            // !EF.Property(e, "IsDeleted"))
            var not = Expression.Not(genericMethodCall);

            // e => !EF.Property(e, "IsDeleted"));
            var lambda = Expression.Lambda(not, parameter);
        }