Mysql按列添加组

I want to add the additional column at the end from mysql query which show the distinct records(parent_id) with increment values(column "x" in image) as attached sample in image. Sample mysql query i tried :

select *, count(parent_id) as x
from businessDemands
where zip='123'
group by sub_Category_name
order by category_name desc

I want same result as in image as of now its comming same with incorrect values in "x" column

You can do this in MySQL using variables:

select t.*,
       (@rn := if(@p = parent_id, @rn,
                  if(@p := parent_id, @rn + 1, @rn + 1)
                 )
       ) as x
from t cross join
     (select @p := -1, @rn := 0) params
order by parent_id;

EDIT:

Variables and GROUP BY don't work well together. Use a subquery:

select t.*,
       (@rn := if(@p = parent_id, @rn,
                  if(@p := parent_id, @rn + 1, @rn + 1)
                 )
       ) as x
from (select . . .
      from businessDemands bd
      where zip = '123'
      order by parent_id
     ) t cross join
     (select @p := -1, @rn := 0) params
order by parent_id;

Fix the subquery so it is either a valid GROUP BY or remove the aggregation entirely.