Entity
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Which of these is an entity a school database could store data about?
2. In a database design, each entity becomes...
3. Which is the better name for an entity table that stores data about books?
4. A canteen database stores data about each order a student places. Is Order an entity?
5. A library needs to record each person's name, phone number and email. Which of these is the entity?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1CREATE TABLE student (studentId INT, firstName VARCHAR(30)); | ACREATE TABLE student (studentId INT); CREATE TABLE subject (subjectId INT); | |
| 2Entity: Event (e.g. a school sports carnival) | BCREATE TABLE book (bookId INT, title VARCHAR(50)); | |
| 3An entity name should be a singular noun because each row is one example of it | CThe entity Student becomes one table, named with a singular noun | |
| 4Each entity becomes its own table, so students and subjects need two tables | DAn entity can be an event, not just a person, place or thing | |
| 5CREATE TABLE students (studentId INT); | EA student's name is an attribute, not an entity. It should be a column in the student table, not its own table. | |
| 6CREATE TABLE studentName (studentId INT); | FThe entity name is plural. It should be the singular noun student, because each row is one student. |
C
Definitions
entity
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
CREATE TABLE ____ (bookId INT, title TEXT);
2.
____________ Place (placeId INT, city TEXT);
3.
INSERT INTO _______ VALUES (1, 'Ava');
4.
SELECT firstName ____ Student;
5.
CREATE TABLE Event (_______ INT, name TEXT);
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
-- Entity: student
B
CREATE TABLE Students (
C
studentId INT,
D
firstName VARCHAR(30)
E
);
Question 2
A
-- Library entities
B
CREATE TABLE Book (id INT);
C
CREATE TABLE Member (id INT);
D
CREATE TABLE Loan (id INT;
Question 3
A
-- Each entity is one table
B
CREATE Teacher TABLE (
C
teacherId INT,
D
name VARCHAR(30)
E
);
Question 4
A
-- Sport entities
B
CREATE TABLE Player (id INT);
C
CREATE TABLE Teams (id INT);
D
CREATE TABLE Game (id INT);
Question 5
A
CREATE TABLE Pet (id INT);
B
INSERT INTO Pet VALUES (1);
C
INSERT INTO Pet VALUES (2);
D
SELECT * FROM Pets;
Answer Key
Entity
Section A: Quick Questions
Q1
B — Student
Q2
B — One table
Q3
A — Book
Q4
A — Yes, an event can be an entity
Q5
A — Member
Section B: Match the Pairs
Q1
CREATE TABLE student (studentId INT, firstName VARCHAR(30)); → The entity Student becomes one table, named with a singular noun
Q2
Entity: Event (e.g. a school sports carnival) → An entity can be an event, not just a person, place or thing
Q3
An entity name should be a singular noun because each row is one example of it → CREATE TABLE book (bookId INT, title VARCHAR(50));
Q4
Each entity becomes its own table, so students and subjects need two tables → CREATE TABLE student (studentId INT);
CREATE TABLE subject (subjectId INT);
Q5
CREATE TABLE students (studentId INT); → The entity name is plural. It should be the singular noun student, because each row is one student.
Q6
CREATE TABLE studentName (studentId INT); → A student's name is an attribute, not an entity. It should be a column in the student table, not its own table.
Section C: Definitions
Q1
entity — A type of thing a database stores data about, such as a student, book or order. Each entity becomes one table, and its name is a singular noun.Section D: Fill in the Blanks
Q1
CREATE TABLE Book (bookId INT, title TEXT);Q2
CREATE TABLE Place (placeId INT, city TEXT);Q3
INSERT INTO Student VALUES (1, 'Ava');Q4
SELECT firstName FROM Student;Q5
CREATE TABLE Event (eventId INT, name TEXT);Section E: Spot the Error
Q1
B — Entity names are singular nouns. The table stores many students, but the entity is one type of thing, so it should be CREATE TABLE Student (
Q2
D — The closing bracket is missing. The entity table Loan should end with ) before the semicolon: CREATE TABLE Loan (id INT);
Q3
B — The keywords are in the wrong order. The Teacher entity becomes a table with CREATE TABLE Teacher (
Q4
C — Entity names are singular nouns. The entity is Team, not Teams, so it should be CREATE TABLE Team (id INT);
Q5
D — The entity was made into a table called Pet, so the query must use that same name. It should be SELECT * FROM Pet;