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Final Review

Final Review. Sunday March 13th. Databases. Entities/Rows Attributes/Columns Keys Relationships Schema Instance. Databases. Entities/Rows -”theme” Attributes/Columns - characterisitics about entities Keys - unique row identifiers -EVERY ROW MUST HAVE ONE

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Final Review

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  1. Final Review Sunday March 13th

  2. Databases • Entities/Rows • Attributes/Columns • Keys • Relationships • Schema • Instance

  3. Databases • Entities/Rows -”theme” • Attributes/Columns - characterisitics about entities • Keys - unique row identifiers -EVERY ROW MUST HAVE ONE • Relationships - associations among data - • Foreign keys • Schema - Table structure • Instance - Table contents

  4. Good databases • One copy of data - Why? • Relationships between tables - How?

  5. Databases operations • Project • Select • Union • Difference • Product

  6. Databases operations • Project - pick columns • Select - pick rows • Union - combine two tables • Difference - remove one table from another • Product - create all possible pairs

  7. Info Retrieval • Use QUERIES to retrieve info from databases • Relationships • One - to - one • One - to - many • Many - to - many • Primary keys • Foreign keys

  8. Info retrieval • One - to - many: • The ONE is the primary key and is used as a foreign key in the MANY’s table • Many - to - many: • Cross reference table! To reduce into 1 - to- many

  9. Forms • GUI • Front end of the database • Easier way to: • Present info • Add content • Adding an image to a form • Database stores a link to the image file (same as html)

  10. Reports • Make DB look pretty! • Easier way to: • Arrange data • Present data • How is it done in access: • Wizard - easier • Design mode - customizable

  11. Binary numbers • What does each number position represent? • Convert from hex to decimal • Convert from binary to decimal • Why represent info. Using binary numbers?

  12. Representing info in binary • Text • Color • Pictures • Sound • Anything! • How are continuous signals represented in binary?

  13. Representing info in binary • Text • Color • Pictures • Sound • Anything! • How are continuous signals represented in binary? FIRST DISCRETIZE (OR DIGITIZE), THEN REPRESENT!

  14. Privacy online • Privacy Statements • Cookies • Good? • Bad? • Can I do anything about it?

  15. Privacy principles • Limited collection • Knowledge and consent whenever appropriate • Quality • Relevant to the purpose. Accurate and complete • Purpose • Purpose should be stated. Limit use to purpose • Use Limitation • Limit the use to the purpose unless authorized

  16. Privacy Principles • Security • Against disclosure, access, misuse, modification, destruction, loss • Openness • Let users know anything you can! • Participation • Let users have control over their data (as much as possible • Accountability • The controller is accountable

  17. First midterm stuff • HTML

  18. Second midterm stuff

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