public virtual IQueryable <Doctor> SearchDoctor(DoctorSearchModel model)
        {
            var name         = new SqlParameter("@name", (object)model.Name ?? DBNull.Value);
            var specialtyId  = new SqlParameter("@specialtyId", (object)model.SpecialtyId ?? DBNull.Value);
            var hospitalId   = new SqlParameter("@hospitalId", (object)model.HospitalId ?? DBNull.Value);
            var departmentId = new SqlParameter("@departmentId", (object)model.DepartmentId ?? DBNull.Value);

            var doctors = Doctors.FromSqlRaw("SELECT * FROM SearchDoctors(@name, @specialtyId, @hospitalId, @departmentId)",
                                             name, specialtyId, hospitalId, departmentId);

            return(doctors);
        }