database Quiz 3 Revision

which of these show all the data from employees table?

• select * from employees;

• SELECT * FROM employees;

• both are correct

if you want to make the id column a primary key what do you add in the blank

create table students

(id number(8) _______,

name varchar2(20),

address varchar2(20));

if i wanted to add a column to have a unique constraint which of these do i choose ?

create table students

(id number(10) primary key,

name varchar2(20),

phone number(9) _______);

• Not repeated

• constraint phone_unique unique

• constraint (phone unique) unique

• constraint phone_unique unique (phone)

which of these is a named primary key constraint

• student_id number(8) constraint student_pk primary key

• student_id number(8) primary key

• neither of them

which of these data types is better suited for Bahraini dinars

• number(10,3)

• varchar2(10)

• number(10)

what do you type to calculate the average value of the salary column

select ___________ from employees;

how do you ensure that no null values are entered into the address column?

create table students

(student_id number(10),

name varchar2(20),

address varchar2(40) ______ );

how do i check that the salary is higher than 300?

create table employees

(id number(10) primary key,

name varchar2(10),

salary number(5) check ( ________ ) );

how do i type to complete the command below to see all the columns in the students table?

select _ from students;

select first_name ___________ from employees;

how do i show the column name as First Name instead of first_name?

• you cant do that

• as 'First Name'

• as "First Name"

• == 'First Name'