数据库系统概念第三章答案.pptVIP

3 SQL 3-8 a. Select count * from license a Where exists select 1 from owns b,person c where a.car b.license and b.driver_id c.drive_id and ‘John Smith’ b. Update license set damage_amount 3000 where report_number ‘AR2197’ and car ‘AABB2000’ 3-9 a. select employee_name from works where company_name ‘First Bank Corporation’ b. select a.employee_name,b.employee_name from employee a,employee b where a.city b.city and exists select 1 from works c,works d, company e,company f where a.employee_name c.employee_name and b.employee_name d.employee_name and pany_name pany_name and pany_name pany_name and e.city f.city 3-9 c. select a.employee_name,b.employee_name from employee a,employee b where a.city b.city and a.street b.street and exists select 1 from mamages c,manages d where a.employee_name c.employee_name and b.employee_name d.employee_name and c.manager_name d.manager_name d. select employee_name from works a where a.salary select avg b.salary from works b where pany_name pany_name group by pany_name e. select company_name from works group by company_name having sum salary all select sum salary from works group by company_name 3-9 e. select company_name from select company_name,sum salary ,rownum from works group by company_name order by sum salary where rownum 1; select company_name from select company_name,rank over order by sum salary rank from works group by company_name where rank 1; 3-10 a. update works set salary salary*1.1 where company_name ‘First Bank Corporation’ b. update works a set salary salary*1.1 where company_name ‘First Bank Corporation’ and exists select 1 from manages b where a.employee_name b.manager_name c. delete works where company_name ‘Small Bank Corporation’ 3-11 select A from R select * from R where B 17 select * from R,S select A,F from R,S where C D 3-12 select * from r1 union select * from r2 select * from r1 intersect select * from r2 select * from r1 minus select * from r2 3-14 create view man_e