[Relational data model: constraints] Suppose each of the update operations liste

Question

[Relational data model: constraints] Suppose each of the update operations listed below is applied to the database state shown in Figure 5.6. Depending on whether there is any integrity violation by each operation, either state that there is no violation or state the integrity constraint violated and why.

a) Insert <’333445555’, 2, 15.0> into WORKS_ON.

b) Insert <’333445555’, null, null> into WORKS_ON.

c) Insert <’333445555’, 30, null> into WORKS_ON.

d) Insert <’333445555’, 5, 10.0> into WORKS_ON.

e) Delete <’333445555’, 3, 10.0> from WORKS_ON.

Figure 5.6 One possible database state for the COMPANY relational database schema. EMPLOYEE Fname Minit Lname John FranklinT Wong 333445555 1955-12-08 638 Voss, Houston, TX M 40000 8886655555 Alicia JenniferSWallace 987654321 1941-06-20 291 Berry, Bellaire, TX Ramesh K Narayan 666884444 1962-09-15 975 Fire Oak, Humble, TX M 38000 3334455555 Joyce Ahmad V Jabbar 987987987 1969-03-29 980 Dallas, Houston, TX M 25000 9876543214 James Sex |Salary_Super_ssn Dno B Smith 123456789 1965-01-09 731 Fondren, Houston, TX M 30000 333445555 5 sn Bdate Address J Zelaya 9998877771968-01-19 3321 Castle, Spring, TX F 25000 987654321 4 F 43000 888665555 A English453453453 1972-07-31 5631 Rice, Houston, TX F 25000 333445555 5 E Borg 888665555 1937-11-10 450 Stone, Houston, TXM 55000 NULL DEPARTMENT DEPT LOCATIONS Dnumber Dlocation Houston Stafford Bellaire Sugarland Houston Dname Dnumber Research Administration Headquarters Mgr ssn 333445555 987654321 888665555 Mgr start date 1988-05-22 1995-01-01 1981-06-19 4 4 WORKS ON PROJECT

Explanation / Answer

Question 1

No violation is there.This values will be accepted to the table.

Question 2

Integrity constant is violated.

The Pno column cannot be null.

Question 3

No violation is there.This values will be accepted to the table.

Question 4

The table will accept the value but there will be a problem as there is no pnumber as 5.So for future reference it will give errors.

Question 5

No violation is there.This values will be accepted to the table.

Question 6

No violation is there.This values will be accepted to the table.

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.