Download
introduction to database and microsoft access n.
Skip this Video
Loading SlideShow in 5 Seconds..
Introduction to Database and Microsoft Access PowerPoint Presentation
Download Presentation
Introduction to Database and Microsoft Access

Introduction to Database and Microsoft Access

145 Vues Download Presentation
Télécharger la présentation

Introduction to Database and Microsoft Access

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Introduction to Database and Microsoft Access

  2. What is a database? • A collection of information about one subject (ex. contacts, customer information, sports team information) • Managed by a Database Management System aka DBMS (ex. Access) • A DBMS contains tools for sorting, analyzing, extracting, and summarizing data in a database

  3. Terminology • Table: a collection of- • Fields: the columns in the table • Example: Name, Address, Postal Code, Phone • Records: the rows in a table • Example: Pat McQuaidinfo, Rosemary Wild info • Data values: the actual data in each record (row) • Example: Pat McQuaid, 12 Any Street, 93407, 756-7833

  4. A Flat File vs. a Database An Excel spreadsheet stores data in a “flat file” with all data values in single row

  5. An Example of a flat file in Excel Customer Orders

  6. Relational Database A database consists of a set of tables with each table formed to contain only data related to a single aspect of a problem. This is why a database is termed “relational.”

  7. Relational Database Concepts • Primary KeyA unique identifier needed to get to a particular record in a database (ex. customer number, item number, order number) • Foreign KeyA key in a table that is also a primary key in another table. Used to link related tables.

  8. Breaking a flat file into a set of tables- Customers Orders Items (Products) *Foreign Key *Primary Key in Red

  9. More Database Concepts • Tables in a relational database are connected to each other via keys • A key is a unique identifier (ex. Social Security Number, Drivers License Number, Customer Number, Order Number, Product Number)

  10. A few additional points • All tables in a relational database should have a primary key • A primary key may consist of more than 1 field • A primary key/foreign key relationship is used to logically connect tables to enable navigation through stored data