Introduction to Databases and Data Management

Data and Information

• Data is raw, unprocessed facts
• Information is processed data, given meaning
• Example: 31106 could mean 31,106 people in a town, 31,106 km on a car clock, a cost of $311.06 or $31,106, or an access code for a door lock

What Is a Database?

• An organized collection of related data
• Examples include address books, phone books, library catalogs, and university course lists
• A database doesn't need to be on a computer

Database Management System (DBMS)

• Software that manages and organizes a database
• Enables tasks like creating databases
• Selecting and displaying data
• Sorting data
• Querying data
• Calculating and formatting data
• Reporting data
• Examples include Microsoft Access, Word, and Excel

Database Organization

• Data is stored in tables
• Tables consist of rows (records)
• Records consist of fields (columns)
• Example: A table about people might have fields for first name, last name, address, etc.

Data Organization

• Data is in tables
• Columns are fields
• Rows are records

Types of Databases

• File processing system: "Flatfile database," basic filing system, one table (like a spreadsheet)
• Relational database: The most common type; many tables linked together

Language Classes - Flatfile

• Database containing details of students enrolled in language classes
• Includes fields for first name, last name, address, suburb, city, phone, language, day, and fee

Language Classes - Relational

• Database with linked tables for student information and class details
• Includes tables for students (with fields like Student ID, first name, last name, etc.) and classes (with fields like Class ID, language, etc.)
• Linked tables use Class ID

In a Relational Database the Tables Are Joined

• Tables are linked to avoid data redundancy (e.g. data entered twice) and for easier maintenance.
• Relational databases combine data from multiple tables.

Relational DBMS vs. File Management

• Avoids data redundancy
• Maintains data integrity, ensuring accuracy
• Saves space
• More flexible, adding new tables
• Better for data sharing across a network
• Easier for backups

Design Dictionary

• A plan for the fields in a database table
• Helps to create an organized and effective database
• Includes fields like field name, data type, length, format, and examples.

Data Dictionary in MS Access

• Defines fields and names
• Specifies data type characteristics
• Identifies the primary key field

The Primary Key

• A special field for identifying each record uniquely within a table
• Usually a sequential auto-number, or a unique identifier
• Examples include student ID numbers, bank account numbers, etc.

Common Data Types

• Text: Any combination of letters, numbers, and special characters, limited size
• Memo: Same as text, but unlimited size
• Number: Used for mathematical calculations, numerical values only
• Date/Time: Formats for storing dates and times
• Currency: Storing currency values
• AutoNumber: Automatic sequential numbers commonly used as primary keys
• Yes/No: Boolean values (true/false)

The Ideal Database System

• Preserves data integrity, ensuring data accuracy
• Promotes data independence, used in one format, avoiding redundancy
• Ensures data security, with data protection
• Enables data maintenance (adding, updating, deleting records

Components of a Relational Database

• Tables: Raw data stored in rows and columns
• Query: Extracts data based on specific criteria
• Forms: Used for entering and viewing data
• Reports: Used for printing queries or tables
• Macros: Automate parts of the database
• Modules: Small programs for advanced tasks

Summary

• Databases come in many forms
• DBMS is software to manage databases on a computer
• Databases use fields to create records which make up tables
• File processing systems use a single table
• Relational databases link multiple tables using a primary key
• Valuable data has defined characteristics.

Explore the fundamentals of data, information, and databases in this quiz. Understand the organization of databases, the role of a Database Management System (DBMS), and how data is structured in tables. Test your knowledge on these essential concepts for managing information effectively.