1Database Management Systems Exercise II  Consider the following relational schemas:  employee (person_name, street, city)  company (company_name, city)  works (person_name, company_name, salary)  manages (person_name, manager_name)

2Database Management Systems Q1: Find the names of employees who work for some company in Boston.  person_name (works  city = “Boston” (company)) selectdistinct w.person_name fromworks w, company c wherew.company_name = c.company_name andc.city = “Boston”

3Database Management Systems Q2: Find the streets of employees who work for all companies in Boston.  street (employee (  person_name, company_name (works)   company_name (  city = “Boston” (company)))) select distinct e.street from employee e, works w where e.person_name = w. person_name and not exists ((select company_name from company where city = “Boston”) except (select company_name from works w1 where w1.person_name = w.person_name))

4Database Management Systems Q3: Find the names of all managers who earn more than $10,000.  person_name (  salary > (works))   manager_name (manages) select distinct w.person_name from works w, manages m where w.person_name = m.manager_name and w.salary > 10000

5Database Management Systems Q4: Find the names and cities of employees who work for First Bank Corporation and earn more than $10,000.  person_name, city (employee (  salary >  company_name = “First Bank Corporation” (works))) select person_name, city from employee where person_name in (select person_name from works where salary > and company_name = “First Bank Corporation”)

6Database Management Systems Q5: Find the names of managers who manage all employees working for First Bank Corporation.  manager_name, person_name (manages)   person_name (  company_name = “First Bank Corporation” (works)) select m.manager_name from manages m where not exists ((select person_name from works where company_name = “First Bank Corporation”) except (select m2.person_name from manages m2 where m.manager_name = m2.manager_name))

7Database Management Systems  Find the names of the employees whose salaries are higher than those of all employees living in Los Angeles. (One employee may have several works.)

8Database Management Systems  Find the names of the managers whose salaries are higher than that of at least one employee that they manage. (One employee may have several works.)