Answer:
select s.sname from supplier s,product p,supply su where s.s#=su.s# and p.p#=su.p# and p.p_name like 'chairs' and p.price>300
Explanation:
First of all, we need to select all the required columns from the specific tables so that the data in those columns can be display by executing this SQL query.
As the task at hand is to find all supplier names and cities who supply expensive chairs therefore we need to join three tables in order to look for the supplier name selling the highest prices.
In the above SQL query, the conditons "s.s#=su.s# and p.p#=su.p#" will join tables and the conditons "p.p_name like 'chairs' and p.price>=300" will be used to search for the chair with price greater than $300.
