What are all the department stores?
select * from department_stores
What are all the department stores that the store chain South has?
select * from department_stores as t1 join department_store_chain as t2 on t1.dept_store_chain_id = t2.dept_store_chain_id where t2.dept_store_chain_name = "South"
How many are there?
select count(*) from department_stores as t1 join department_store_chain as t2 on t1.dept_store_chain_id = t2.dept_store_chain_id where t2.dept_store_chain_name = "South"