显示null而不是num值

Question

我的查询

with with_user_earns as (
            -- get father information (start)
            select father.id, father.str_name, father.id_father, father.ind_father_side_type, 1 as int_user_level from tb_user father where id = @v_user_id

            union all

            -- get son information (stop condition)
            select son.id, son.str_name, son.id_father, son.ind_father_side_type, WUE.int_user_level + 1 
            from tb_user as son inner join with_user_earns as WUE on son.id_father = WUE.id 
            where son.id_father is not null and WUE.int_user_level < @v_max_level
        )

        select aux.* 
        from (

            -- show result
            select with_user_earns.id id_son, with_user_earns.str_name str_son_name, with_user_earns.id_father, father.str_name str_father_name, with_user_earns.ind_father_side_type, with_user_earns.int_user_level, isnull(sum(o.int_score), 0) as int_score
            from with_user_earns inner join tb_order o on o.id_user = with_user_earns.id
                                 inner join tb_user as father on father.id = with_user_earns.id_father                   
            where o.dt_insert between @v_cycle_begin and @v_cycle_end and o.ind_payment_status = 3
            group by with_user_earns.id, with_user_earns.str_name, with_user_earns.id_father, with_user_earns.ind_father_side_type, with_user_earns.int_user_level, father.str_name

        ) as aux
        order by aux.int_user_level, aux.id_son

table with_user_earns包含许多用户（多个nivel层次结构）。 然后我想加入tb_order以获得int_score 0如果用户什么都不卖，并且如果用户出售任何我想要的总和。

我试过把左连接，全外连接，......但是没有人完美地工作

需要做什么？

My result:
id_son int_score
1   100
2   11100
3   100
10  300

Expected result:
id_son int_score
1   100
2   11100
3   100
4   0
5   0
6   0
7   0
8   0
9   0
10  300