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Final Review

This review covers essential database concepts including entities, attributes, keys, and relationships, laying a foundation for understanding database schemas and instances. Key database operations like project, select, union, difference, and product clarify how data can be manipulated and retrieved through queries. Additionally, we delve into privacy principles related to data collection and usage, emphasizing the importance of security and user consent. This guide aims to provide a holistic understanding of how databases work, their operations, and key considerations for maintaining user privacy.

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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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