database - SQL Quiz that I am working on some sample work -


my database

       employee(employee-name, street, city)        works(employee-name, company-name, salary)        company(company-name, city)        manages(employee-name, manager-name)
  1. find ’john doe’s manager’s name.
  2. find employee’s whom ’john doe’ manages.
  3. find companies have 75 employees.
  4. find in how many cities ’first bank corp.’ located.
  5. find how many employees work ’citybank’ in new york.

i'm stuck on #3, far have

select company-name  company  inner join works.employee-name, works.company-name company-name = '75'

i know wrong? close? havent looked @ 4 , 5

select "company - name", count(*) works group "company - name" having count(*) = 75

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