BUILDING SOLUTIONS: Database, system & Application Development Tools
Database- Collection of data organized in a manner that allows access, retrieval, and use of that data
Data- Collection of unprocessed items
(text, numbers, images, audio, video)
Information-Processed data
(organized, meaningful & useful)
Database software / Database management system( DBMS)
-Create a computerized database
-Add, modify, and delete data
-Sort and retrieve data
-Create forms and reports from the data
Levels:
1: Characters - Numbers, letters, blank space, punctuation marks, or other symbols
2: Fields- a combination of one or more related characters
(Field name, Field size, Data type)
3; Records-a group of related fields
4: data files- a collection of related records
File maintenance- the procedures that keep data current ( adding, modifying & deleting records)
Validation- compares data with a set of rules or values to determine if the data meets certain criteria
- alphabetic/ numeric check
-Range check
-Consistency check
-Completeness check
-Check digit
-Other checks
file processing system:
-Each department has its own set of files
-Redundant data
-Isolated data
Database approach:
-Programs and users share data
-Reduced data redundancy
-Improved data integrity
-Shared data
-Easier access
-Reduced development time
Disadvantages of a database approach
-more complex than a file processing system
-Require more memory and processing power
-Data can be more vulnerable
Web databases : offers information ( jobs, travel,destinations,Television programming,Photos,movies,videos,local and national weather,sporting events& legislative info)
Data model: defines how users view the organization of the data
( including Relational database, Object-oriented database (OODB),Multidimensional and other database types)
data dictionary : contains data about each file in the database and each field in those files
provides several tools that allow users and programs to retrieve and maintain data in the database
-Query language
-Query by example
-Form
-Report writer
query: a request for specific data from the database
query language: consists of simple, English-like statements that allow users to specify the data to display, print, store, update, or delete
Structured Query Language (SQL): a popular query language that allows users to manage, update, and retrieve data
form: a window on the screen that provides areas for entering or modifying data in a database
report writer: allows users to design a report on the screen, retrieve data into the report design, and then display or print the report
A DBMS provides means to ensure that only authorized users access data
- Access privileges
- Principle of least privilege policy
A DMBS: provides a variety of techniques to restore the database to a usable form in case it is damaged or destroyed
- Backup, log, recovery utility, continuous backup
information system: a collection of hardware, software, data, people, and procedures that work together to produce information
System development: a set of activities used to build an information system
System development activities: grouped into phases, and is called the system development life cycle (SDLC)
System development phases:
1) planning
2) analysis
3) design
4) implementation
5) support & security
general guidelines:
-Group activities into phases
-Involve users
-Define standards
should involve representatives from each department in which the proposed system will be used
systems analyst: responsible for designing and developing an information system
Project management :the process of planning, scheduling, and then controlling the activities during system development
elements in planning& scheduling a project:
scope,Required activities,Time estimates for each activity,Cost estimates for each activity,Order of activities,Activities that can take place at the same time
popular tools used:
Gantt and PERT charts
Feasibility : a measure of how suitable the development of a system will be to the organization
including:
- Operational feasibility
- Schedule feasibility
- Technical feasibility
- Economic feasibility
Documentation : the collection and summarization of data, information, and deliverables
Gathering data& information :
-Review documentation
-Observe
-Survey
-interview
-JAD Sessions
-research
During a JAD session, the systems analyst is the moderator, or leader of the discussion. Another member, called the scribe, records facts and action items assigned during the session
Planning phase :begins when the steering committee receives a project request
Four major activities are performed:
1) Review and approve the project request
2) Prioriitize the project request
3) allocate resources
4) form a project development team
analysis phase :
- Conduct a preliminary investigation
-Determines the exact nature of the problem or improvement
-Interview the user who submitted the request- Perform detailed analysis
-Study how the current system works
-Determine the users’ wants, needs, and requirements
-Recommend a solution
- Perform detailed analysis
system proposal :assesses the feasibility of each alternative solution
steering committee ; discusses the system proposal and decides which alternative to pursue
- Modify existing system
- Buy retail software
- Use web apps
- Build custom software
- Outsource
design phase ; consists of two major activities
- acquire hardware and software
- Develop all of the details of the new or modified information system
- Develop all of the details of the new or modified information system
To acquire the necessary hardware and software:
-Identify technical specifications
- Solicit vendor proposals
-Test and evaluate vendor proposals
-Make a decision
develop detailed design specifications
-Database design
-Input and output design
-Program design
Systems analysts typically develop two types of designs for each input and output
-mock-up
-layout chart
prototype (proof of concept) is a working model of the proposed system’s essential functionality
The purpose of the implementation phase is to construct the new or modified system and then deliver it to users
- develop programs and apps
- install and test the new system
- train users
- convert to the new system
Various tests should be performed on the new system
- unit test
Verifies that each individual program or object works by itself
- system test
Verifies that all programs in an application work together properly
- integration test
Verifies that an application works with other applications
- acceptance test
Checks the new system to ensure that it works with actual data
Training involves; showing users exactly how they will use the new hardware and software in the system
- one-on-one class
- classroom-style lectures
- web-based training
- direct conversion
- parallel conversion
- phased conversion
- pilot conversion
can be used to change from the old system to the new system
support and security phase; to provide ongoing assistance for an information system and its users after the system is implemented
- perform maintenance activities
- monitor system performance
- assess system security
programming language: a set of words, abbreviations, and symbols that enable a software developer to communicate instructions to a computer or mobile device
application development tool : provides a means for creating, designing, editing, testing, and distributing programs and apps
procedural language : the programmer writes instructions using English-like words that tell the computer what to accomplish and how to do it
The C programming language: used to write many of today’s programs
compiler : converts the entire source program to machine language before executing it
An interpreter : translates and executes one instruction at a time
object-oriented programming (OOP) language allows system developers to implement objects in a program
- other advantages:
Objects can be reused
Developers create applications faster
Most object-oriented application development tools are IDEs
C++ is an extension of the C programming language
-Additional features for working with objects
Visual Studio : is Microsoft’s suite of object-oriented application development tools that assists software developers in building programs and apps for Windows or any operating system that supports the Microsoft .NET Framework
4GL (fourth-generation language) is a nonprocedural language that enables users and software developers to access data in a database (One popular 4GL is SQL)
Classic programming languages include:
-BASIC
-COBOL
-FORTRAN
-RPG
application generator is a program that creates source code or machine code from a specification of the required functionality
-Often bundled as part of a DBMS
A macro is a series of statements that instructs a program or app how to complete a task
You usually create the macro in one of two ways:
-record the macro
-write the macro
HTML is a special formatting language that software developers use to format documents for display on the web
XML allows web developers to create tags that describe the structure of information
- WML is a subset of XML and is used to design pages specifically for microbrowsers
add interactivity on webpages
to add special media effects (such as animated graphics, scrolling messages, calendars, and advertisements) , web developers write small programs called scripts using a variety of scripting languages
- JavaScrpt
- Perl
- PHP
- Python
- Ruby