1 / 5

Assignment #3 due Wed., Nov. 14, 2012 1. (30) Exercise 7.17 on Page 235

Assignment #3 due Wed., Nov. 14, 2012 1. (30) Exercise 7.17 on Page 235 Show the result of the following queries as they would apply to the database of Figure 7.6 (using the figures available on my home page). Retrieve the name and address of all employees who

walter
Download Presentation

Assignment #3 due Wed., Nov. 14, 2012 1. (30) Exercise 7.17 on Page 235

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Assignment #3 • due Wed., Nov. 14, 2012 • 1. (30) Exercise 7.17 on Page 235 • Show the result of the following queries as they would apply to the database of Figure 7.6 (using the figures available on my home page). • Retrieve the name and address of all employees who • work for the ‘research’ department: RESEARCH_DEPT  DNAME = ‘Research’(DEPARTMENT) DNUMBER = DNO EMPLYEE) RESEARCH_EMPS  (RESEARCH_EPT RESULT  FNAME, LNAME, ADDRESS(RESEARCH_EMPS) Yangjun Chen ACS-3902

  2. For every project located in ‘Stafford’, list the project number, the controlling • department number, and the department manager’s last name, address, and the • birthdate. STAFFORD_PROJS  PLOCATION = ‘Stafford’(PROJECT) DNUM=DNUMBER DEPARTMENT) CONTR_DEPT  (STAFFORD_PROJS MGRSSN=SSN EMPLOYEE) PROJ_DEPT_MGR CONTR_DEPT RESULT  PNUMBER,DNUM,LNAME,ADDRESS,BDATE(PROJ_DEPT_MGR) Yangjun Chen ACS-3902

  3. (C) Retrieve the names of employees who have no dependents. ALL_EMPS  SSN(EMPLOYEE) EMPS_WITH_DEPS  ESSN(DEPENDENT) EMPS_WITHOUT_DEPS  (ALL_EMPS – EMPS_WITH_DEPS) RESULT  LNAME, FNAME(EMPS_WITHOUT_DEPS * EMPLOYEE) Yangjun Chen ACS-3902

  4. 2. (30) Exercise 7.18 on Page 235 • Specify the following queries on the database schema shown in Figure 7.5, using the relational operators defined in the relational algebra. Also show the result of each query as it would apply to the database of Figure 7.6. (Using the figures available on my home page). • a. Retrieve the name of all employees in department 5 who work more than 10 hours per week on the ‘Product X’ project. • b. List the names of all employees who have a dependent with the same first name as themselves. • c. Find the names of all employees who are directly supervised by ‘Franklin Wong’. • d. For each project, list the project name and the total hours per week (by all employees) spent on that project. • e. Retrieve the names of all employees who work on every project. Yangjun Chen ACS-3902

  5. (in third edition) • 3. (20) Exercise 7.22 on Page 237 • Consider the relation • CLASS(Course#, Univ_Section#, InstructorName, Semester, BuildingCode, • Room#, TimePeriod, Weekdays, CreditHours). • This represents classes taught in a university, with unique Univ_Section#. Identify what you think should be various candidate keys, and write in your own words the constraints under which each candidate key would be valid. • 4. (20) Exercise 7.27 on Page 239 • Consider the two tables T1 and T2 shown in Figure 7.21 (available on my home page). Show the results of the following operations: • a. T1 T1.p=T2.AT2 b. T1 T1.Q=T2.BT2 • c. T1 T1.P=T2.AT2 d. T1 T1.Q=T2.BT2 • e. T1  T2 f. T1 (T1.P=T2.A and T1.R=T2.C)T2 Yangjun Chen ACS-3902

More Related