SQL查询某一行数据并查询以该行某个字段为父ID的数据的行数？

SQL查询某一行数据并查询以该行某个字段为父ID的数据的行数？

//这样只会查询出parent_id的重复次数并分组展示
select 
      
        parent_id,
        count(parent_id) countnumber 
        from table_name c
         group by parent_id 
             order by countnumber desc;

单独查行数倒是可行，但是如何做到如图所示的效果
大概就是这样，如图所示

又想有原始数据，又想有统计数据，那就关联查询啊

select * 
from tableA a
left join (
    select parent_id,COUNT(0) as cnt
    from tableA
    group by parent_id
) b on a.id=b.parent_id
where a.parent_id is null

select  parent_id,
        (select count(parent_id) from table_name where parent_id=c.id)  countnumber 
        from table_name c where parent_id is null
         group by id order by countnumber desc;