Question

No particular DBMS in mind, how would I do the following:

# There are many tables per one restaurant, many napkins per one table
# Pseudo SQL

SELECT RESTAURANT WHERE ID = X;
SELECT ALL TABLES WHERE RESTAURANT_ID = RESTAURANT.ID;
SELECT ALL NAPKINS WHERE TABLE_ID = TABLE.ID;

But, all in one query? I’ve used a JOIN to get all the tables in the same query as restaurant, but is it possible to get all napkins for each table as well, in the same query?

Answer 1

select * -- replace * with the columns you need...
from restaurant as r 
    inner join tables as t on t.restaurant_id = r.id
    inner join napkins as n on n.table_id = t.id
where r.id = [restaurant id]