Rapid Application Development - CMU Personal...
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Rapid Application Development
Chapter 6: Development Database Application
Tools: Microsoft Access
Dr.Orawit Thinnukool
College of Arts, Media and Technology, Chiang Mai University
Cr: fisher.osu.edu
Contents
• Introduction to Database
• Database Component
• Purpose of Database System
• Database Management Systems
• Database System Hardware
• Database System Software
• Planning the design of database
• Database Application
• Introduction: What is Access?
• What are these objects in ACCESS
• Data Type :Access
• Relational Database
• The database design process
• Logically structuring data
Introduction to Database
• A database is a place to store information. That information
could be sales figures, an inventory of computers you own, a
list of key customers, timesheet information; the possibilities
are endless. By having the database on your site, you can
easily share the information with people who need access to
it.
• The best way to think of a database is as a table. The
columns in the table are called fields. There are many types
of fields you can create: text, numeric, currency, names,
dates, to name a few. The rows in the table are
called records. The records contain all the database
information.
Introduction to Database
A database is much more powerful than a simple table.
With a table, you can only look at the information in the one way that the
table is designed. A database allows you to create many views of your
information. Each view allows you to:
Select the fields displayed in the view.
Pick the order in which the fields appear.
Set up a filter to control which records appear in the view.
Sort the order in which the records appear.
Total up fields in the view.
View fields from more than one database.
Introduction to Database When you create your own
database, you determine how
the information appears, what
the names of the fields are,
what the views look like, and
who has access to the
database.
If you already have information
that you would like in your
database, you can import that
information into the database.
You can also export information
from your database for use in
another program, such as
Microsoft Excel
Database Component
1. Data : In DBMS, databases are defined, constructed and then
data is stored,
2. Database Application: program contains statements that
request the DBMS to perform operation on database. The
operations may include updating, deleting data etc .
3. Database Management System: It is the set of
programs used to handle the database and to control and
manage the overall computerized database
4. Database Server: database server is a computer program that
provides database services to other computer programs
or computers, as defined by the client–server model. The term may
also refer to a computer dedicated to running such a program.
5. Database Administrator : A person who is responsible for
managing the overall database management system is called
database administrator or simply DBA.
Database Management Systems
• A database management system (DBMS) is an
aggregate of data, hardware, software, and users that
helps an enterprise manage its operational data
• The main function of a DBMS is to provide efficient and
reliable methods of data retrieval to many users
• Most DBMSs deal with several users who try
simultaneously to access several data items and,
frequently, the same data item
(Oracle)
Microsoft SQL Server
MySQL
Microsoft Access
IBM DB/2
Sybase
SAP DB
Database System Hardware
• A categorize computer memory into two classes:
internal memory and external memory ; internal
memory is permanent, such as ROM
• We are interested here only in memory that can
be changed by programs. This memory is often
known as RAM.
Database System Software
• Users interact with database systems through query
languages. The query language of a DBMS has two
broad tasks: to define the data structures that serve as
receptacles for the data of the database, and to allow the
speedy retrieval and modification of data.
DBMS software usually contains application development tools
in addition to query languages. The role of these tools is to
facilitate user interface development. They include forms
systems, procedural and nonprocedural programming
languages that integrate database querying with various user
interfaces, etc.
Purpose of Database System
• Nowadays, database applications were built on top of file
systems
- Data redundancy and inconsistency
Multiple file formats, duplication of information in different files
- Difficulty in accessing data
Need to write a new program to carry out each new task
- Data isolation
multiple files and formats
- Integrity problems
Integrity constraints
Hard to add new constraints or change existing ones
Purpose of Database System
- Atomicity of updates
Failures may leave database in an inconsistent state with partial
updates carried out
E.g. transfer of funds from one account to another should either
complete or not happen at all
- Concurrent access by multiple users
Concurrent accessed needed for performance
Uncontrolled concurrent accesses can lead to inconsistencies
- Security problems
Database Models
A database model is a type of data model that determines
the logical structure of a database and fundamentally
determines in which manner data can be stored, organized,
and manipulated. The most popular example of a database
model is the relational model, which uses a table-based
format.
1. Hierarchical database model
2. Network model
3. Relational mode l** we also uses this model
4. Object model
Planning the design of database
• When designing your database, you need to consider:
• What fields should be in the database? This determines
what type of information can be stored in the database.
• What views of the information are needed? This
determines how users can see the information and what
appears in printed reports or screen.
• What are the permission levels for the database? Who
should have access to this information? Who can add
information? Who can edit it?
Database Application
A database application is a computer
program whose primary purpose is
entering and retrieving information from
a computerized database.
Database application comes from the
practice of dividing computer software
into systems programs, such as the
operating system, compilers, the file
system, and tools such as the database
management system, and application
programs, such as a payroll check
processor. On a standard PC running
Microsoft Windows, ATM, Registration
app et al.
Database Application
-Banking: all transactions
-Airlines: reservations, schedules
-Universities: registration, grades
-Sales: customers, products, purchases
-Manufacturing: production, inventory,
orders, supply chain
-Human resources: employee records,
salaries, tax deductions
Introduction: What is Access?
• Microsoft Access is a relational database management system
(DBMS). At the most basic level, a DBMS is a program that
facilitates the storage and retrieval of structured information on
a computer’s hard drive. Examples of well-know industrial-
strength relational DBMSes include
• Oracle
• Microsoft SQL Server
• IBM DB2
• • Informix
Well-know PC-based (“desktop”) relational DBMSes include
• • Microsoft Access
• • Microsoft FoxPro
• • Borland dBase
Introduction: What is Access?
Microsoft generally likes to incorporate as many features as
possible into its products. For example, the Access
package contains the following elements:
• A relational database system that supports two industry
standard query languages: Structured Query Language
(SQL) and Query By Example (QBE);
• A full-featured procedural programming language—
essentially a subset of Visual Basic,
• A simplified procedural macro language unique to
Access;
• A rapid application development environment complete
with visual form and report development tools;
Introduction: What is Access?
• A sprinkling of objected-oriented extensions;
• Various wizards and builders to make development
easier
What are these objects in ACCESS
When you create a database, Access offers you Tables,
Queries, Forms, Reports, Macros, and Modules. Here's a
quick overview of what these are and when to use them.
1. Tables.
2. Queries
3. Forms
4. Reports
5. Macros
6. Modules
What are these objects in Access
• 1.Table : All data is stored in tables. When you create a new table,
Access asks you define fields (column headings), giving each a
unique name, and telling Access the data type. Use the "Text" type
for most data, including numbers that don't need to be added e.g.
phone numbers or postal codes
• 2. Forms: The basic form has an appearance similar to an index
card: it shows only one record at a time, with a different field on each
line. If you want to control how the records are sorted, define a query
first, and then create a form based on the query. If you have defined
a one-to-many relationship between two tables, use the "Subform"
Wizard to create a form which contains another form. The subform
will then display only the records matching the one on the main form.
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What are these objects in Access
3. Reports: If forms are for input, then reports are for output. Anything
you plan to print deserves a report, whether it is a list of names
and addresses, a financial summary for a period, or a set of mailing
labels.
4. Wizards : Again the Access Wizards walk you through the process
of defining reports table form and queries, which are also automatic
created.
5. Macros. An Access Macro is a script for doing some job. Macros
can also be used to set one field based on the value of another (the
"SetValue" action), to validate that certain conditions are met before
a record saved (the "CancelEvent" action) etc.
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Data Type :Access
Think of a field's data type as a set of qualities that applies to all the
values contained in the field and that determines what kind of data
those values can be. There are ten different data types in Access:
• Attachment Files, such as digital photos. Multiple files can be
attached per record. This data type is not available in earlier versions
of Access.
• AutoNumber Numbers that are automatically generated for each
record.
• Currency Monetary values.
• Date/Time Dates and times.
• Hyperlink Hyperlinks, such as e-mail addresses.
• Memo Long blocks of text and text that use text formatting. A
typical use of a Memo field would be a detailed product description.
Data Type :Access
• Number Numeric values, such as distances. Note that there
is a separate data type for currency.
• OLE Object OLE objects, such as Word documents.
• Text Short, alphanumeric values, such as a last name or a
street address.
• Yes/No Boolean values.
NOTE THAT : Sometimes, the data in a field may appear to be one data
type, but is actually another. For example, a field may seem to contain
numeric values but may actually contain text values, such as room
numbers. You can often use an expression to compare or convert values
of different data types.
Relational Database
A database is a means of storing information in such a way
that information can be retrieved from it. In simplest terms, a
relational database is one that presents information in tables
with rows and columns. A table is referred to as a relation in
the sense that it is a collection of objects of the same type
(rows).Data in a table can be
related according to
common keys or
concepts, and the
ability to retrieve
related data from a
table is the basis for
the term relational
database.
Relational Database
• Data in a table can be related according to common
keys (Primary Key (PK) or Florien Key (FK) )
The database design process
1. Determine the purpose of your database
This helps prepare you for the remaining steps.
2. Find and organize the information required
Gather all of the types of information you might want to record in the
database, such as product name and order number.
3. Divide the information into tables
Divide your information items into major entities or subjects, such as
Products or Orders. Each subject then becomes a table.
4. Turn information items into columns
Decide what information you want to store in each table.
Each item becomes a field, and is displayed as a column in the table.
The database design process
5. Specify primary keys
Choose each table’s primary key. The primary key is a column that is used to
uniquely identify each row. An example might be Product ID or Order ID.
6. Set up the table relationships
Look at each table and decide how the data in one table is related to the
data in other tables. Add fields to tables or create new tables to clarify the
relationships, as necessary.
7. Refine your design
Analyze your design for errors. Create the tables and add a few records of
sample data. See if you can get the results you want from your tables. Make
adjustments to the design, as needed.
8. Apply the normalization rules
Apply the data normalization rules to see if your tables are structured
correctly. Make adjustments to the tables, as needed.
Logically structuring data
Once the relationships and dependencies
amongst the various pieces of information have
been determined, it is possible to arrange the data
into a logical structure which can then be mapped
into the storage objects supported by the database
management system. In the case of relational
databases the storage objects are tables which
store data in rows and columns.
Reference
https://support.office.microsoft.com/en-us/article/Database-design-basics-1eade2bf-
e3a0-41b5-aee6-d2331f158280?CorrelationId=224322a9-d5f8-4ac7-bef2-
2fdbfc28a3d5&ui=en-US&rs=en-US&ad=US
Gehani, N. (2006). The Database Book: Principles and practice using MySQL. 1st
ed., Summit, NJ.: Silicon Press
Database design basics. (n.d.). Database design basics. Retrieved May 1, 2010,
from http://office.microsoft.com/en-us/access/HA012242471033.aspx
Teorey, T.; Lightstone, S. and Nadeau, T.(2005) Database Modeling & Design:
Logical Design, 4th edition, Morgan Kaufmann Press. ISBN 0-12-685352-5
http://www.comnetsite.com/access-tech.php