assume 6th class  is a category assigned to a user 1 which is having three sub-categories maths,physics,chemistry. 7th class is also a category assigned to a user 2 which is having three sub-categories english,biology,science but when  i need  to display userids  with their  category names………but iam getting output+sub-categories of another category……. ex:   1   6th class  [...]