Download Questions A 1 Name of Field Example Data Data Type Title ( Mr, Ms

Questions A
1
Name of Example Data
Data Type
Field
Title
( Mr, Ms, Mrs,
words
Dr )
Phone
1566-655-1172
numbers
Number
Sex
M
or F
Logical/Boolean
Country
Botswana
words
Data of
01/10/03
Dates
4
numbers
Birth
Years at
address
2
Items of data
Tick if data type is
logical/Boolean
Driving (yes or no)
Logical
Sex (M or F)
Logical
Size (S, M, L, XL, words
XXL)
Airport code
Car
numbers
registration text
number
Date of purchase
date
Car type (manual or Logical
automatic)
Fuel type (diesel or Logical
petrol)
Are you hungry
Logical
Is your name long Logical
or short
File : A collection of related records. A
record of this class is called a table. if you
combine the tables for all classes you get
a files.
Record: All the data relating to a single
thing or person. A record is made up of
fields. Name, Age, Sex DOB, Grade
Field : a single item of data age
Data : a fact about something.
Information:
Data
+
Meaning
=
information.
02/11/11.
you need the field name
(data).
Feb 11, 2011
Information:
November 02, 2011
Data is pointless and confusing without
meaning.
Key field
: A piece of data which
everyone has in common but this data is
unique to each person. Student ID number.
Passport Number. National ID Number.
Social Security Number.
Flat-file Database: a 1 document database,
like one Excel Spreadsheet.
Relational
Spreadsheets
together.
Question B
1
Database:
which
3
are
Excel
connected
Number Make
DB51
Aston
Model
Year
DB7
2009
360
2008
Martin
CAB
Ferrari
360M
GT
Modena
X34 Ferrari
FER
MAS 12
355
2000
Spider
Maserati
3200
2001
GTA
FG09
Porche
911
2009
FRT
Turbo
M3 MMM BMW
M3 Conv 2010
T433
XK8
YTH
Jaguar
2009
a Give the names of TWO fields shown in
the above table.
Alphanumeric
words
b Give the name of the field that should be
chosen as the key field. make
c Explain why the field you have chosen
for your answer to part (b) should be
chosen as the key field.
Most of the customers would buy cars due
to the companies which makes it
d How many records are there in the
table?
4
2 Most schools now use databases to
store details about each pupil. The table
shows some of the field names and data
types stored in one pupil database.
Field name
Unique
Data Type
Pupi Number
Number
First name
Words
Surname
Text/Alphanumeric
First Line Address
Text/Alphanumeric
Second
Line Text/Alphanumeric
Address
Postcode
number
Land line No
Text/Alphanumeric
Date0fBirth
Free
Date
Schoo Logical
lMeals(Y/N)
a Give the most appropriate data types for
the following fields:
I
First name
ii
Postcode
All in table
iii Free School Meals
b Give the names of three other fields that
are likely to be used in this database.
Age Sex,
c Explain which field is used as the key
field in the database and why such a field
is necessary.
UPN, because the school need the UPN
to identify the students
d It is important that the data contained in
this database is accurate.
Describe how TWO different errors could
occur when data is entered into this
database.
Transposition errors - where digits are
incorrectly reversed when being entered
into a database.
Transcription errors - where data copied
from forms is misread.
e Explain how the errors you have
mentioned in part(d) could be detected or
prevented.
you can fix transcription errors by verifying
the data after you enter it.
you can fix transposition errors by adding
a check digit at the end of a long number.
3
a Explain what is meant by a flat-file
database.
a 1 document database, like one Excel
Spreadsheet.
b Explain what is meant by a relational
database.
3
Excel
Spreadsheets
which
are
connected together.
c Describe an application where a flat-file
database would be suitable.
Excel
4
Databases are of two types: flat file and
relational.
a Describe two differences between a
flat-file
database
and
a
relational
database.
flat-file only includes one, while the
relational database has more than one
b A dress hire company needs to store
details of dresses, customers, and rentals.
They want to store these details in a
database.
Which type of database do you suggest
and give two reasons for your answer.
Flat-files cheaper and easy to make.
Test your self
The following notes summarize this topic.
The notes are incomplete because they
have words missing. Using the words in
the list below, copy out and complete the
sentences A to N, underlining the words
that you have inserted. Each word may be
used more than once.
Analogue to digital
record
analogue
real
foreign
digital to
key field
Boolean
Links
relational
digital
A
Redundancy
analogue
fields
alphanumeric
table
Numeric data can be in two forms
integer or real.
B
Letters and numbers together are
called alphanumeric data.
C
Logical or Boolean data can have only
one of two values: True or False.
D
A key field
is a piece of data in a
database system that is unique to a
particular records.
E
All the data relating to a single thing or
person is called a record.
F
A record consists of many fields.
G
A database where the data is held in
two or more tables with links established
between them is called a relational
database.
H
Flat-file databases only contain one
table of data.
I
Relational databases have links called
relationships between the tables.
J
In order to create a relationship a
primary key in one table is linked to the
same field called a foreign key in the other
table.
K
Flat
files
may
suffer
from
Redundancy data where a lot of the data
in the table is repeated.
L
An
analogue
signal
from
a
temperature sensor will need to be
converted into a digital signal before it can
be processed by a computer.
M
Changing from an analogue to a
digital signal is performed using an
Analogue to digital converter.
N
In order to control a device such as a
motor, a digital signal from the computer
will need to be change into an one and
this is done using a digital to analogue
converter.
REVISION QUSTIONS
1. Here is a sample of the data that is to
be stored in an employee database.
He data items shown are the
employees’ surname, initial, street,
postcode, and telephone number.
Ahmed ,V, 123 The High Street,
L23 6DE, 0151-002-1112
Delos, N 64 North Way, L9 8SS,
0151-002-0011
Doyle, B, 12 Crosby Road, L23
7YH, 0151-002-1212
Carrol, A, 15 Barkfield Drive, L23
7YH, 0151-002-0899
Conway, T, 6 Windle Hey, L23
6ER, l23 6er, 0151-003-0899
Hoch, J, 4 Empress Road, L22
7ER, 0151-003-9090
Hoch, J, 4 Empress Road, L22
7ER, 0151-003-9090
A
A table is to be set up with four
fields. Give field names for the four
fields that would be suitable for the
above set of data items.
Word litters Alphanumeric numbers
B
The person who is designing the
database looks at the sample of data
above and notices that there are wo
people with the same surname and
initial who live at the same address.
I
Explain why the surname would
be an unsuitable key field.
Many gays have the same surname.
Ii
It is decided that each employee
should be given a unique number.
What would be a suitable field name
for this field.
S792831293813 like this
2. A store keeps details about their
customers and their orders in an
information handling systems. Part of
the data in this system Is shown
below:
Customer Name
Item Size
number
code
Cost Deliver
2314
J.Hughes 464 Small $290 N
9819
D. Wong 255 Large $767 Y
1311
C. Khled 747 Small $239 N
8276
K. Lee
299 Small $200 Y
9223
F.Smith
108 Large $823 Y
A
Give the names of two key fields
used in the above table.
Customer number and Item code
B
There is one “Boolean” field in
this database. Give the name of it.
Delivery
C
Give the names of two other fields
that could be sensibly used in this
table other than customer name,
customer address, and customer
telephone number.
ID and AGE
D
The store offers free delivery on
all items with a cost greater than
$200.
How many of the customers
shown would qualify for the free
delivery?
3. Sensors such as temperature,
moisture, and light sensors are used
to monitor the growing conditions in a
greenhouse.
A
Explain why computers are not
able to read the data directly from
these sensors.
B
Give the name of the device
needed to enable the computer to
read this data.