Page 304 - Information_Practice_Fliipbook_Class11
P. 304
Table: PROJECT ASSIGNED
Registration_ID ProjectNo
IP-101-15 101
IP-104-15 103
CS-103-14 102
CS-101-14 105
CS-101-10 104
a. Name primary key of each table.
b. Find foreign key(s) in table PROJECT-ASSIGNED.
c. Is there any alternate key in table STUDENT? Give justification for your answer.
d. Can a user assign duplicate value to the field RollNo of STUDENT table? Jusify.
Ans. a. The name of the primary key of each table is as follows:
Table Primary Key
Student RollNo
Project ProjectNo
ProjectAssigned {Registration_ID, ProjectNo}
Note that: Registration_ID of STUDENT is an alternate key.
b. The ProjectNo is the foreign key for PROJECT-ASSIGNED table.
c. Yes, Name and Registration_ID can be an alternate keys in the STUDENT table as it sores unique values for each rows.
d. No, as we have already defined RollNo as a primary key. So user cannot assign duplicate value to the field RollNo.
13. For the above given database STUDENT-PROJECT, can we perform the following operations?
a. Insert a student record with missing roll number value.
b. Insert a student record with missing registration number value.
c. Insert a project detail without submission-date.
d. Insert a record with registration ID IP-101-19 and ProjectNo 206 in table PROJECT-ASSIGNED.
Ans. a. No, because RollNo is a primary key, so it can not be NULL.
b. Yes, because Registration_ID is a foreign key in the STUDENT table, so the record with missing Registration_ID can be
inserted.
c. Yes, detail of project can be inserted provided a null constraint is not set for SubmissionDate.
d. No, because Registration_ID with value IP-101-19 does not exist in STUDENT. Also, ProjectNo with value 206 does
not exist in PROJECT.
14. Match the following clauses with their respective functions.
ALTER Insert the value in a table
UPDATE Restrictions on columns
DELETE Table definition
INSERT INTO Change the name of a column
CONSTRAINTS Update existing information in a table
DESC Delete an existing row from a table
CREATE Create a database
Ans.
ALTER Change the name of a column
UPDATE Update existing information in a table
DELETE Delete an existing row from a table
INSERT INTO Insert the values in a table
CONSTRAINTS Restrictions on columns
DESC Table definition
CREATE Create a database
15. Choose appropriate answer with respect to the following code snippet.
CREATE TABLE student (
name CHAR(30),
student_id INT,
290 Touchpad Informatics Practices-XI

