Announcements• If you didn’t already do the “Week 0” exercise, you should do ASAP!• Sign up for Lynda.com ASAP – $21.67 US for duration of semester – Videos to watch will be assigned shortly after today’s lecture – Bring your headphones to all future labs!• Join the BSYS 2060 group on zenportfolios.ca if you didn’t already – Upload an avatar if you didn’t already – We will start using this online group more in the weeks to come, especially for the project
If you didn’t do this already…Go to zenportfolios.ca, log-in, click on Groups, search for 2060Then join the BSYS-2060-2012 group
“Inasmuch as you need to know how to readEnglish, you need to have someunderstanding of the code that builds theWeb,” said Sarah Henry, 39, an investmentmanager who lives in Wayne, Pa. “It isfundamental to the way the world isorganized and the way people think aboutthings these days.”
We live in an information age where data is king.
Data often most valuable asset of a companye.g. Aeroplan worth more than Air Canada
Diaspora The average middle aged person has their data spread out over A 1000 different database locations Many “fly by Self-hosted night” Web 2.0 Website apps containing all your data You control You don’t completely control the data at all Not so easy... convenient Trend is towards you controlling your data
What are the main data entities?These will become your tables
What are the required fields and field data types?
What are the relationships between the tables?
Select your tools?e.g. MS Access, MS SQL, MySQL, OracleWhat is being used now if anything?
Be careful of the hammer! To a hammer, everything looks like a nail. If you only know MS Access, you may see always see MS Access as the solution even when it’s not. If you only know MS Excel, it seems like the perfect choice!Source:http://www.flickr.com/photos/fixersphotos/3199566032/
NormalizationA brief introduction to the first three forms...
“Normalization”• In the field of relational database design, normalization is a systematic way of ensuring that a database structure is suitable for general-purpose querying and free of certain undesirable characteristics—insertion, update, and deletion anomalies—that could lead to a loss of data integrity. Codd, E.F. The Relational Model for Database Management: Version 2. Addison-Wesley (1990), p. 271
“...insertion, update, and deletion anomalies...” Until a Course Code is assigned to this record, it can not be inserted in the table
“...insertion, update, and deletion anomalies...” An edit made to one record may not be made to ALL records for the same employee
“...insertion, update, and deletion anomalies...” If the Course Code is deleted the information for the Faculty Member will be lost.
Three Normal Forms• 1NF – Eliminate repeating groups – No redundant data• 2NF – Eliminate independent data – All fields depend on Primary Key• 3NF – Eliminate dependency on non-key fields – Fields do not depend on each other