CS404 T09a

1. What is the correct SQL command to create a new table named EMP with columns empno and ename?

• CREATE EMP (empno, ename);

• CREATE TABLE EMP (empno NUMBER, ename VARCHAR2(20));

• CREATE TABLE EMP VALUES (empno, ename);

• NEW TABLE EMP (empno NUMBER, ename CHAR);

2. Which SQL keyword is used to remove a table from the database?

• REMOVE

• DELETE

• TRUNCATE

• DROP

3. What happens when you use the TRUNCATE TABLE emp command?

• The table structure is deleted

• All data is removed but the table remains

• The table is locked

• Only the first row is deleted

4. What is the maximum length for a VARCHAR2 field in Oracle?

• 256

• 1000

• 2000

• 4000

5. Which of the following statements defines a PRIMARY KEY constraint at table level?

• PRIMARY KEY empno

• CONSTRAINT pk_emp PRIMARY KEY (empno)

• PRIMARY (empno)

• CONSTRAINT PRIMARY KEY (empno)

6. Which of the following is a valid CHECK constraint?

• CHECK salary < 10000

• CHECK (salary > 0)

• CHECK salary IS NOT NULL

• CHECK (salary = 'HIGH')

7. What does the following statement do?
ALTER TABLE emp DROP COLUMN project;

• Deletes the project column from emp

• Deletes the entire emp table

• Renames the column

• Converts column type

8. What is the correct way to insert a row into the DEPT table with only deptno and loc?

• INSERT INTO DEPT VALUES (50, 'NEW YORK');

• INSERT INTO DEPT (deptno, loc) VALUES (50, 'NEW YORK');

• INSERT VALUES INTO DEPT (50, 'NEW YORK');

• INSERT INTO DEPT SET deptno = 50, loc = 'NEW YORK';

9. When defining a NUMBER(4,2) column, what is the maximum value you can store?

• 9999.99

• 999.99

• 99.99

• 9.9

10. What is the outcome if you try to DROP a table with existing foreign key dependencies without using CASCADE CONSTRAINTS?

• The table is deleted, and dependent constraints are kept

• The table is dropped without warning

• Oracle raises an error and prevents the table from being dropped

• The related foreign keys are turned into NULLs