L7

1. App Design for Business
Topic: Database
Topic Number: 7

2. Key topics / learning outcomes
of this lecture
• Database use within an Android App;
• Learn the concept of creating an
SQLite Database;
• A look at SQL (Structured Query
Language);
2

3. What is a database?
B4004A L1 3

4. Different types of Database
B4004A L1 4

5. Android Database
The database used with Android is called
SQLite.
This database is a trimmed down
version of MySQL, PostgreSQL and
other similar databases.
B4004A L1 5

6. SqLite Android Database
• it is a relational database;
• SQLite was originally designed for defence purposes;
• it has no administrator;
• it uses less data types than other typical relational
databases:
– int: a signed integer;
– real: a floating-point number;
– text: a text string;
– blob: a ‘blob’ of data;
• It is ‘shipped’ with Android:
– Each APP has its own SQLite database.
B4004A L1 6

7. Usual steps to design a database
• Create a Data dictionary
– List all the data terms,
• example: name, address, postcode;
– Allocate a data type to the field
• example: the _id field has a data type of int;
• Create an Input/Output list
– identify all inputs and outputs,
• example: input name, address, postcode
• example: output list of all address in postcode W1.
B4004A L1 7

8. Usual steps to design a database
• Identify Entities
– list relationships
• one to one
• one to many
• many to many
• List attributes
– their data type;
– their default value;
• Normalize
– reduce duplication of data storage
• create new tables to reduce duplication of fields;
• Add keys
– primary key
– foreign keys
B4004A L1 8

9. Data Flow Diagrams
• Once all the information gathering is complete, a
database design is moved on to the drawing
stage;
• The first drawing will be very concise, almost like
a ‘birds eye view’ of the database, usually named
a Context drawing;
• Each section of the Context drawing will be
expanded level by level until the detail is
exhausted, therefore no more detailed level may
be reached.
B4004A L1 9

10. Context Drawing
B4004A L1 10

11. An Example of a Data Flow Diagram
Source: http://conta11.my3gb.com/examlpe-of-data-flow-diagram.html
B4004A L1 11

12. An example of database tables
together with their relationships
Source: http://carlibrary.org/CarDatabases.htm
B4004A L1 12

13. Databases comprise of …
• Tables
– Usually a database will contain more than one
table:
– example PERSON, PERSON_ADDRESS.
• Fields
– Fields are ‘table columns’ with a heading and
column content
• Records
– are ‘table rows’ with an ‘id’ and row content
B4004A L1 13

14. … a closer look at databases …
B4004A L1 14

15. A table within a Database
_id Name Password
1 Pearson 123
2 John abcd
3 Viz 5678
This table will
have a name,
for example:
PERSON
B4004A L1 15
This database
will have a
name, for
example:
ADDRESS_BOOK

16. Relational Tables
address_id Address _id
1 1 Smith Street 2
2 80 Strand 1
3 6 Jones Square 3
_id Name Password
1 Pearson 123
2 John abcd
3 Viz 5678
This table will
have a name,
for example:
PERSON
B4004A L1 16
This table will
have a name, for
example:
PERSON_ADDRESS

17. Relational Tables
addres
s_id
Address Address_Type _id
1 1 Smith Street Halls of Residence 2
2 80 Strand Office 1
3 6 Jones Square Private Rented 3
4 2 The Farmhouse Home 2
_id Name Password
1 Pearson 123
2 John abcd
3 Viz 5678
This table will
have a name,
for example:
PERSON
B4004A L1 17
This table will
have a name, for
example:
PERSON_ADDRESS

18. Relational Tables
addres
s_id
Address Address_Type _id
1 1 Smith Street Halls of Residence 2
2 80 Strand Office 1
3 6 Jones Square Private Rented 3
4 2 The Farmhouse Home 2
_id Name Password
1 Pearson 123
2 John abcd
3 Viz 5678
Foreign
Key
B4004A L1 18
Primary
Key
Fields
(Columns)
Records
(Rows)

19. Use SQL to access data, for example
SQL Syntax
SELECT * FROM PERSON INNER JOIN PERSON_ADDRESS ON PERSON._id =
PERSON_ADDRESS._id WHERE PERSON.Name=John;
B4004A L1 19
SELECT column_name(s)
FROM table1
INNER JOIN table2
ON table1.column_name=table2.column_name
WHERE table1.column_name= ? ;
Actual SQL derived from the syntax

20. More SQL (Structured Query
Language) Resources
• SQL is a standard database protocol:
– adopted by most ‘relational’ databases;
• Provides syntax for interaction with databases;
• For more info, visit W3schools for their
tutorial on SQL:
– here you will find all the SQL syntax needed to
interact with your database.
http://www.w3schools.com/sql
B4004A L1 20

21. Seminar
• In the seminar for this lecture, you will be
copying and pasting code into IntelliJ and
running a database.
• You will be making some changes to the fields
and tables to learn how you may tailor the
database to suit a different application.
B4004A L1 21

22. Workshop
• In the workshop for this lecture, you will be
viewing a series of tutorials explaining more
about SQLite.
B4004A L1 22

23. Essential work for next week
• Please consult the OLE for details of:
– Essential readings*
– Seminar/workshop preparation work*
– Recommended further readings
– Any additional learning
* Essential readings and preparation work must always be completed in time
for the next session
23

24. End of presentation
© Pearson College 2013