Database Database


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Class Definition--encapsulation

  • Class Definition--encapsulation

    • Class Name
    • Properties
    • Methods
  • Inheritance Relationships

    • Generic classes
    • Focus on differences
    • Polymorphism
    • Most existing DBMS do not handle inheritance












Common data types

  • Common data types

    • Text
      • Fixed length 1 to 64 K bytes
      • Variable length 1 to 2 G bytes
    • Memo/Note
    • Numeric
      • Byte 1 byte 0 to 255
      • Boolean 2 bytes True or False
      • Integer 2 bytes -32,768 to 32,767 (no decimal points)
      • Long 4 bytes -2,147,483,648 to 2,147,483,647 (no decimal points)
      • Floating 4 bytes 1.401298E-45 to 3.402823E38
      • Double 8 bytes 4.94065645841247E-324 to 1.79769313486232E308
      • Currency 8 bytes -922,377,203,685,477.5808 to 922,377,203,685,477.5807
    • Date/Time 8 bytes Jan 1, 100 to Dec 31, 9999
    • Objects/Raw binary
      • Any type of data supported by the machine
      • Pictures, sound, video . . .






Business Event

  • Business Event

    • Item is sold.
    • Decrease Inventory count.
  • Data Event

    • Inventory drops below preset level.
    • Order more inventory.
  • User Event

    • User clicks on icon.
    • Send purchase order to supplier.


Business Process: Ship Product

  • Business Process: Ship Product



Design is harder on large projects.

  • Design is harder on large projects.

    • Communication with multiple users.
    • Communication between IT workers.
    • Need to divide project into pieces for teams.
    • Finding data/components.
    • Staff turnover--retraining.
  • Need to monitor design process.

    • Scheduling.
    • Evaluation.
  • Build systems that can be modified later.

    • Documentation.
    • Communication/underlying assumptions and model.


Project planning software

  • Project planning software

    • Schedules
    • Gantt charts
  • CASE tools

  • Groupware tools

    • Track changes
    • Document work
    • Track revisions


Computer-Aided Software Engineering

  • Computer-Aided Software Engineering

    • Diagrams (linked)
    • Data Dictionary
    • Teamwork
    • Prototyping
      • Forms
      • Reports
      • Sample data
    • Code generation
    • Reverse Engineering




















Simple form based on one table (Animal).

  • Simple form based on one table (Animal).

  • But also need lookup tables for Category and Breed.



http://time-post.com/dbdesign

  • http://time-post.com/dbdesign

  • Students and instructors need only an Internet connection and a Java-enabled Web browser.

  • Instructor can sign up free by sending email to: jpost@time-post.com

  • Instructors set up the class and select assignments.

  • Students create accounts and work on the assignments.

  • The system provides immediate feedback in the form of comments and questions for each proposed table.







Right click in the main drawing window and select the option to Add table.

  • Right click in the main drawing window and select the option to Add table.

  • Right click the gray bar at the top of the table, select the Rename table option and enter “Customer”

  • Drag the Generate Key item onto the new Customer table.

  • Right click on the new column name, select the Rename option and enter “CustomerID”



The Customer table has a generated key of CustomerID

  • The Customer table has a generated key of CustomerID

  • Each column in the table represents data collected for each customer.

  • Each column depends completely on the primary key.





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