Fundamentals of Fundamentals of Database DesignDatabase Design

John Villamil-CasanovaJohn Villamil-Casanova

Executive Vice President & CIOExecutive Vice President & CIO

The Aspira AssociationThe Aspira Association

202.835.3600 ext. 123202.835.3600 ext. 123

jvillamil@aspira.orgjvillamil@aspira.org

AgendaAgenda

Introduction and participants needsIntroduction and participants needs

We will review “what is a database;”We will review “what is a database;”

Understand the difference between data Understand the difference between data and information;and information;

What is the purpose of a database system;What is the purpose of a database system;

How to select a database system;How to select a database system;

Database definitions and fundamental Database definitions and fundamental building blocks;building blocks;

Agenda (2)Agenda (2)

Database development: the first steps;Database development: the first steps;

Quality control issues;Quality control issues;

Data entry considerations;Data entry considerations;

What is a databaseWhat is a database

A database is any organized collection of A database is any organized collection of data.data. Some examples of databases you Some examples of databases you may encounter in your daily life are: may encounter in your daily life are: a telephone book a telephone book T.V. Guide T.V. Guide airline reservation system airline reservation system motor vehicle registration records motor vehicle registration records papers in your filing cabinet papers in your filing cabinet files on your computer hard drive.  files on your computer hard drive. 

Data vs. information:Data vs. information:What is the difference?What is the difference?

What is data?What is data? Data can be defined in Data can be defined in

many ways. Information many ways. Information science defines data as science defines data as unprocessed information.unprocessed information.

What is information?What is information? Information is data that Information is data that

have been organized and have been organized and communicated in a communicated in a coherent and meaningful coherent and meaningful manner. manner.

Data is converted into Data is converted into information, and information, and information is converted information is converted into knowledge.into knowledge.

Knowledge; information Knowledge; information evaluated and organized evaluated and organized so that it can be used so that it can be used purposefully.purposefully.

Why do we need a database?Why do we need a database?

Keep records of our:Keep records of our: ClientsClients StaffStaff VolunteersVolunteers

To keep a record of activities To keep a record of activities and interventions;and interventions;

Keep sales records;Keep sales records;

Develop reports;Develop reports;

Perform researchPerform research

Longitudinal trackingLongitudinal tracking

What is the ultimate purpose of What is the ultimate purpose of a database management a database management

system?system?

DataData InformationInformation KnowledgeKnowledge ActionAction

Is to transformIs to transform

More about database definitionMore about database definition

What is a database? What is a database? Quite simply, it’s an organized collection of data. Quite simply, it’s an organized collection of data.

A database management system (DBMS) such A database management system (DBMS) such as Access, FileMaker, Lotus Notes, Oracle or as Access, FileMaker, Lotus Notes, Oracle or SQL Server which provides you with the SQL Server which provides you with the software tools you need to organize that data in software tools you need to organize that data in a flexible manner. It includes tools to add, a flexible manner. It includes tools to add, modify or delete data from the database, ask modify or delete data from the database, ask questions (or queries) about the data stored in questions (or queries) about the data stored in the database and produce reports summarizing the database and produce reports summarizing selected contents.selected contents.

Let’s explore some examplesLet’s explore some examples

Outlook contactsOutlook contacts

Aspira Association Aspira Association MISMIS

KidTraxKidTrax

GIS-GPS systemsGIS-GPS systems

Types of DatabasesTypes of Databases

Non-relational databasesNon-relational databasesNon-relational databases place information in field categories that we create so Non-relational databases place information in field categories that we create so that information is available for sorting and disseminating the way we need it. that information is available for sorting and disseminating the way we need it. The data in a non-relational database, however, is limited to that program and The data in a non-relational database, however, is limited to that program and cannot be extracted and applied to a number of other software programs, or cannot be extracted and applied to a number of other software programs, or other database files within a school or administrative system. The data other database files within a school or administrative system. The data can only be "copied and pasted.“ Example: a spread sheetcan only be "copied and pasted.“ Example: a spread sheet

Relational databasesRelational databasesIn relational databases, fields can be used in a number of ways (and In relational databases, fields can be used in a number of ways (and can be of variable length), provided that they are linked in tables. It is can be of variable length), provided that they are linked in tables. It is developed based on a database model that provides for logical developed based on a database model that provides for logical connections among files (known as tables) by including identifying connections among files (known as tables) by including identifying data from one table in another tabledata from one table in another table

Selecting a Database Selecting a Database Management SystemManagement System

Database management systems (or DBMSs) can be divided into Database management systems (or DBMSs) can be divided into two categories -- desktop databases and server databases.   two categories -- desktop databases and server databases.  

Generally speaking, desktop databases are oriented toward Generally speaking, desktop databases are oriented toward single-user applications and reside on standard personal single-user applications and reside on standard personal computers (hence the term desktop).  computers (hence the term desktop). 

Server databases contain mechanisms to ensure the reliability Server databases contain mechanisms to ensure the reliability and consistency of data and are geared toward multi-user and consistency of data and are geared toward multi-user applications.applications.

Selecting a database system: Selecting a database system: Need AnalysisNeed Analysis

The needs analysis process will be specific to your organization but, at The needs analysis process will be specific to your organization but, at a minimum, should answer the following questions:a minimum, should answer the following questions:

How many records we will warehouse and for how long?How many records we will warehouse and for how long?

Who will be using the database and what tasks will they perform? Who will be using the database and what tasks will they perform? 

How often will the data be modified?  Who will make these How often will the data be modified?  Who will make these modifications?modifications?

Who will be providing IT support for the database?Who will be providing IT support for the database?

What hardware is available?  Is there a budget for purchasing What hardware is available?  Is there a budget for purchasing additional hardware?additional hardware?

Who will be responsible for maintaining the data?Who will be responsible for maintaining the data?

Will data access be offered over the Internet?  If so, what level of Will data access be offered over the Internet?  If so, what level of access should be supported?access should be supported?

Some DefinitionsSome Definitions

A A File:File: A group or collection of similar records, like INST6031 Fall A group or collection of similar records, like INST6031 Fall Student File, American History 1850-1866 file, Basic Food Group Student File, American History 1850-1866 file, Basic Food Group Nutrition FileNutrition FileAA record book: record book: a "rolodex" of data records, like address lists, a "rolodex" of data records, like address lists, inventory lists, classes or thematic units, or groupings of other inventory lists, classes or thematic units, or groupings of other unique records that are combined into one list (found in unique records that are combined into one list (found in AppleWorks, FileMaker ProAppleWorks, FileMaker Pro software). software).A A fieldfield: one category of information, i.e., Name, Address, Semester : one category of information, i.e., Name, Address, Semester Grade, Academic topic Grade, Academic topic AA record record: one piece of data, i.e., one student's information, a recipe, : one piece of data, i.e., one student's information, a recipe, a test questiona test questionAA layout layout: a design for a database that contains field names and : a design for a database that contains field names and possibly graphics.possibly graphics.

Database Database glossaryglossary

Tables comprise the fundamental building blocks of any database.  If you're familiar with Tables comprise the fundamental building blocks of any database.  If you're familiar with spreadsheets, you'll find database tables extremely similar.  Take a look at this example of spreadsheets, you'll find database tables extremely similar.  Take a look at this example of a table sample database:a table sample database:

The table above contains the employee information for our organization -- characteristics The table above contains the employee information for our organization -- characteristics like name, date of birth and title.  Examine the construction of the table and you'll find that like name, date of birth and title.  Examine the construction of the table and you'll find that each column of the table corresponds to a specific employee characteristic (or each column of the table corresponds to a specific employee characteristic (or attributeattribute in in database terms).  Each row corresponds to one particular employee and contains his or her database terms).  Each row corresponds to one particular employee and contains his or her information.  That's all there is to it!  If it helps, think of each one of these tables as a information.  That's all there is to it!  If it helps, think of each one of these tables as a spreadsheet-style listing of information.spreadsheet-style listing of information.

Fundamental building blocksFundamental building blocks

Where do we start?Where do we start?

Let’s explore your “paper Let’s explore your “paper system”system”

Client intake formsClient intake forms Job application formJob application form Funders reportsFunders reports

Database modeling:Database modeling: Define required fields from Define required fields from

“forms” or required reports“forms” or required reports Avoid repetitionAvoid repetition Keep it simpleKeep it simple Identify a unique identifier Identify a unique identifier

or primary keyor primary key

Some Quality Control Some Quality Control ConsiderationsConsiderations

Remember “garbage in – Remember “garbage in – garbage out”. Some examples garbage out”. Some examples and how to prevent this.and how to prevent this.Quality management Quality management encompasses three distinct encompasses three distinct processes: quality planning, processes: quality planning, quality control, and quality quality control, and quality improvementimprovementQuality PlanningQuality Planning in relation to in relation to database systems design:database systems design:

Who will perform data Who will perform data entry?entry?

Training? On-line help? Training? On-line help? How data entry will be How data entry will be

performed?performed?

Data entry considerationsData entry considerations

Define “must” enter fields – no record is complete Define “must” enter fields – no record is complete unless: such and such is entered;unless: such and such is entered;

Make data entry fool proof. Example: Grade level can Make data entry fool proof. Example: Grade level can be entered as a number (8 or 8be entered as a number (8 or 8thth or eight). By using a or eight). By using a pull-down menu with the correct data format these pull-down menu with the correct data format these mistakes can be avoided.mistakes can be avoided.

Data Entry – additional Data Entry – additional considerationsconsiderations

Barcode scannersBarcode scanners USB orUSB or Wireless attached to a Wireless attached to a

Palm or Pocket PCPalm or Pocket PC

Pocket PCPocket PC WiFi 802.11g, WiFi 802.11g,

BluetoothBluetooth Wireless networks Wireless networks

(real-time on demand (real-time on demand systems) systems)