Chapter 1-Intro to SQL (Chapter 1-3)

Which of the following allows you to add Address column with string value up to 50 characters in your EMP table?

• ALTER TABLE emp ADD address VARCHAR2(50);

• ALTER TABLE emp ADD COLUMN address VARCHAR2(50);

• ALTER TABLE emp ADD address VARCHAR2(30);

• ALTER TABLE emp DROP COLUMN address;

Which is an example of Data Manipulation Language (DML) command?

• CREATE

• INSERT

• ALTER

• DROP

Which is an example of Data Definition Language (DDL) command?

• INSERT

• DELETE

• CREATE

• UPDATE

Which of the following will display all the records in EMPLOYEES table?

• SELECT salary FROM employees;

• SELECT * FROM employees;

• SELECT ALL FROM employees;

Which command will execute properly?

• INSERT INTO emp (101, 'Melissa', 300);

• INSERT INTO emp VALUES (101, Melissa, 300);

• INSERT INTO emp VALUES (101, 'Melissa', 300);

• INSERT INTO emp VALUES ('101', Melissa, '300');

Which command will execute correctly?

• CREATE TABLE emp (ID Number(5), Name Varchar2(25));

• CREATE TABLE emp (ID Number(5), Name Varchar(25));

• CREATE TABLE emp ID Number(5), Name Varchar2(25);

• CREATE TABLE emp (ID Number(5), Name Varchar);

What will be the result If you will execute the following command: DELETE FROM emp;

• The table will be deleted.

• All the records will be deleted.

• The structure of the table will be displayed.

• The statement will not execute.

You want to change the mobile number to 92745612 of Employee 101, which command will execute correctly?

• UPDATE emp SET mobile_number = 92745612 WHERE student_id=101;

• UPDATE emp SET WHERE mobile_number = 92745612;

• UPDATE emp SET mobile_number = 92745612;

• UPDATE emp SET student_id=101;

This constraint cannot accept NULL values.

• CHECK

• NOT NULL

• PRIMARY KEY

• UNIQUE

Which of the following command is the correct syntax for adding primary key constraint in existing table?

• ALTER TABLE <tableName> ADD CONSTRAINT <constraintName> PRIMARY KEY(columnName);

• ALTER TABLE <tableName> ADD CONSTRAINT PRIMARY KEY(columnName);

• ALTER TABLE <tableName> ADD CONSTRAINT <columnName> PRIMARY KEY;

• None of these