Giải chi tiết Lab 3 SQL Hệ CSDL Đại học Bách Khoa HCM 2021 Bài thực hành số 3Bài 1Sử dụng CSDL Company đã tạo trong bài thực hành số 2.Dùng ngôn ngữ SQL thực hiện các câu truy vấn sau:a. Liệt kê tên (FName và Lname) của tất cả nhân viên thuộc department 5 có làm việc cho project‘ProductX’ nhiều hơn 10 giờ một tuần.
Q1a select fname,minit,lname from employee right outer join ( works_on left outer join project on works_on.pno=project.pnumber) on employee.ssn=works_on.essn where employee.dno=5 and project.pname='ProductX' and works_on.hours>10; Q1b select fname,minit,lname from employee right outer join dependent on ssn=essn where employee.fname=dependent.dependent_name; Q1c select sup.ssn,sup.fname from employee emp right outer join employee sup on emp.ssn=sup.superssn where (emp.fname || ' ' || emp.lname)='Franklin Wong'; Q1d select pname, sum(hours) hours from project left outer join works_on on pnumber=pno group by pnumber,pname; Q1e select pname,fname from employee right outer join ( project left outer join works_on on pnumber=pno) on ssn=essn order by pname; Q1f select fname from ( select * from employee minus (select employee.* from employee right outer join works_on on ssn=essn) ); Q1g select dname, avg(salary) avg_sal from department left outer join employee on dnumber=dno group by dnumber,dname; Q1h select avg(salary) avg_female_sal from employee where sex='F'; Q1i select distinct fname,address from (employee left outer join dept_locations on dno=dnumber) left outer join ( works_on left outer join project on pno=pnumber) on ssn=essn where dlocation != 'Houston' and plocation ='Houston'; Q1j select * from ( select * from ( select department.* from department left outer join employee on mgrssn=ssn) minus (select department.* from department left outer join dependent on mgrssn=essn) ); a update employee set address='123 Lý Thường Kiệt F.14 Q.10' where ssn=123456789; b update dependent set relationship='FRIEND' where dependent_name='Joy' and essn=(select ssn from employee where fname='Franklin') c update employee set salary = salary*2 where dno=(select dnumber from department where dname='Research'); d update employee set salary = salary*0.95 where ssn=(select ssn from (select ssn,nvl(sum(hours),0) h_sum from employee left outer join works_on on ssn=essn where h_sum < 40 group by ssn)); a delete from works_on where pno=(select pnumber from project where pname='ProductZ'); delete from project where pname='ProductZ'; b delete from works_on where essn='999887777'; delete from dependent where essn='999887777'; delete from employee where ssn='999887777'; Q2a select ename, deptno, sal from emp where sal >= 1000 and sal 3; Q2n select ename, dept.loc, dept.dname from emp left join dept on dept.deptno = emp.deptno where sal > 1500; Q2o select ename, job, sal, dept.dname from emp left join dept on dept.deptno = emp.deptno where job not in 'clerk' order by sal desc;