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Database Management System Review ICS 100 What is a Database? • Collection of data associated with a topic – Smallest unit of information is a field – Group of related fields is a record • An organized collection of related information Flat vs. Relational • Small number of records: Flat DB Excel spreadsheet • Large number of records: Relational Like the Web Contains more than one table Banner Student names, addresses, phone number Courses Fees Owed Transcripts DBMS • Database Management System – Provides tools to enter, edit and retrieve data • Users – Policemen, librarians, students, retail establishments Commonly Used Software • Microsoft Access* • Paradox • Lotus Approach • Alpha 5 • FileMaker Pro *Access is not available for Macs Structured Query Language SQL http://databases.about.com/od/sql/a/sqlfundamentals.htm Basic Features • Locate information • Display information – Sort information • Watch demo Stop How is it Organized? • Tables are the foundation of a DB • A primary key* is selected • What is a primary key? *needed to link two or more tables Examples of Primary Keys • • • • • SSN Badge Numbers Student ID Number Vehicle ID Number Employee Number Fields Table Last Name First Name Job Title SSN Brown Alice Accountant 123-33-1234 Akiona John 334-65-9876 Joaquin Pablo Sales Manager Receptionist Thomas Sandy Marketing Manager 234-43-4321 789-76-0987 Records Fields and Records • Fields are like columns in a spreadsheet • Records are like rows in a spreadsheet Two Common Views • Data Sheet View – Looks like a table • Design View – Shows fields in a vertical arrangement – Allows formatting of fields Data Types • Numbers – only numbers • Text = everything (0 to 255 characters) • AutoNumber = Access will number each record • Yes/No • Currency • Date/Time • • • • Hyperlink Memo = more text (0 to 6536 characters) OLE Data Properties • Format each data type • Example – Size of a field – Masks for a field Objects • Allow you to use the database • Types of objects – – – – – – – Table Queries Forms Reports Modules Macros Pages Integrity—most important • Keep data accurate • Keep data up to date • Eliminate redundancy Ways to Eliminate Redundancy • • • • Input Mask Use of a form Use of a primary key Other? Input Mask • Analogy to painting • Masking tape “masks” the areas you don’t want to paint • Guides the user in entering data eg. 234-45-4560 Data is Stored on Tables Printed Information Reports Forms Data Queries Tables Opening a Database • Use the Explorer or My Computer to copy the database • You cannot use the Save as command Closing • Databases may require a lot of memory. • If you plan to move a database, invest in a flash drive.