how to filter a table with where

Question

I'm trying to filter my table 'mange' with the condition of customers who eat both the "mexicaine" and the "végétarienne".

I have a table 'mange' which contains 'nom' and 'pizza'

I have tried to filter with

select *
from mange
where ( pizza = 'végétarienne')
and ( pizza = 'mexicaine')

But I don't get anything even though I have some 'nom' who eat both.

Answer 1

SELECT nom, count(distinct pizza) as DistinctpizzaCNt
FROM mange
WHERE ( pizza in 'végétarienne', 'mexicaine')
GROUP BY nom
having count(distinct pizza) = 2 

or use set based logic

SELECT nom
FROM mange
WHERE ( pizza = 'végétarienne')

INTERSECT

SELECT nom
from Mannge
WHERE ( pizza = 'mexicaine')