Question

Data:

1. table shapes: shape_id, shape_name
2. table shape_forms: shape_form_id, shape_id, shape_form
3. shape_form can be: 0 – circle, 1 – square, 2 – triangle – the number of which for each shape is unlimited

I need 2 queries for selecting

1. all shapes which contains in shape_forms both circles and triangles or only circles but not squares or only triangles
2. all shapes which contains in shape_forms only triangles

Please, give me some hints for solving this task!
I’m restricted not to use “group by” for shape_forms but if there is no proper solution

Answer 1

1.

select s.shape_id
from shapes s
inner join shape_forms sf on sf.shape_id = s.shape_id
group by s.shape_id
having 
(
   sum(shape_form = 1) = 0
   and sum(shape_form in (0,2)) >= 2
)
or sum(shape_form <> 0) = 0

2.

select s.shape_id
from shapes s
inner join shape_forms sf on sf.shape_id = s.shape_id
group by s.shape_id
having sum(shape_form <> 2) = 0