partial void Deletetlb_hocbong(tlb_hocbong instance);
 partial void Inserttlb_hocbong(tlb_hocbong instance);
 partial void Updatetlb_hocbong(tlb_hocbong instance);
 private void detach_tlb_hocbongs(tlb_hocbong entity)
 {
     this.SendPropertyChanging();
     entity.tlb_sinhvien = null;
 }