UpdatableExtensionAttribute.PresenceValue property
namespace: Serenity.Data.Mapping assembly: Serenity.Net.Data
This extension should only be inserted if PresenceField value is equal to this one. For example, you might have a PersonType column in PersonRow and student record should only be created (if not already) if PersonType = "Student".
public object PresenceValue { get; set; }