Introduction to Databases

Data vs. Information

Data – a collection of facts made up of text, numbers and dates:

Murray 35000 7/18/86

Information - the meaning given to data in the way it is interpreted:

Mr. Murray is a sales person whose annual salary is $35,000 and whose hire date is July 18, 1986.

What is the ultimate purpose of a database management system?

DataData InformationInformation KnowledgeKnowledge ActionAction

Is to transform

Data driven decision making

What is a Database? A structured collection of related data A filing cabinet, an address book, a telephone

directory, a timetable, etc. Google and your email School Student Information System

Basic Database Concepts

Table– A set of related records

Name: Barry HarrisCollege: MedicineTel: 392-5555

Name: Barry HarrisCollege: MedicineTel: 392-5555

Name: Barry Harris

Field

Record–A collection of data

about an individual item

–A single item of data common to all records

An Example of a Table

Records

Fields

Name GatorLink Phone College

Graff rgraff 392-3900 Pharmacy

Harris bharris 392-5555 Medicine

Ipswich zipswich 846-5656 PHHP

Primary Keys & Foreign KeysName User Phone College

Graff rgraff 392-3900 Pharmacy

Harris bharris 392-5555 Medicine

Ipswich zipswich 846-5656 PHHP

To ensure that each record is unique in each table, we can set one field to be a Primary Key field.

A Primary Key is a field that that will contain no duplicates and no blank values.

What is a Relational Database Management System (RDMS)?

A relational database is a collection of tables from which data can be accessed in many different ways without having to reorganize the database tables.

DON’T DUPLICATE DATA

– That is, once relationships are created, tables can “talk” to each other. We can link (relate) the tables to find data from many different tables.

Relationships

Foreign Keys are keyslink to data in other tables

Input Data with Forms A friendlier view of the database Used for data input, menus, display and printing Can perform calculations and combine fields

Queries A means of asking questions (querying) of your data Can look across a number of Tables and other Queries Can perform Calculations and Combine fields

Introducing Reports Output of information in a printed report Allows you to group and summarize data Can perform calculations and combine fields Cannot edit data Can make labels

Database Options

Consumer Microsoft Excel Microsoft Access FileMaker Pro MySQL (Open Source) Postgres (Open Source)

Enterprise RDMS Oracle IBM/DB2 MS SQL-server Sybase Informix Lotus Notes MySQL (Open Source) Postgres (Open Source)

SQL Structured Query Language (SQL) is used for relational

database “programming.”

SQL is the most commonly used programming language in the world