• Bài giảng Systems Analysis and Design in a Changing World - Chapter 13: Designing DatabasesBài giảng Systems Analysis and Design in a Changing World - Chapter 13: Designing Databases

    Summary (continued)  Object database stores data as collection of related objects and is developed from class diagram  Objects can also be stored within RDBMS  RDBMS cannot store methods  RDBMS cannot directly represent inheritance  Medium and larger information systems typically use multiple databases or database servers in various ge...

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  • Bài giảng Systems Analysis and Design in a Changing World - Chapter 10: The Traditional Approach to DesignBài giảng Systems Analysis and Design in a Changing World - Chapter 10: The Traditional Approach to Design

    Summary (continued)  Structure charts may be based on three-layer architecture  Modules will be clearly identified by layer  Structure chart may be decomposed if layers execute on multiple systems  Structured design may also include:  System flowcharts to show data movement  Module pseudocode to describe internal logic of structure ch...

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  • Bài giảng Systems Analysis and Design in a Changing World - Chapter 8: Evaluating Alternatives for Requirements, Environment, and ImplementationBài giảng Systems Analysis and Design in a Changing World - Chapter 8: Evaluating Alternatives for Requirements, Environment, and Implementation

    Summary (continued)  Determine what alternatives are possible for developing solution  Implementation alternatives include:  Building system in-house  Buying packaged or turnkey solution  Contracting with developer to build it (outsource)  Develop recommendations and present to management to make funding decisions

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  • Bài giảng Systems Analysis and Design in a Changing World - Chapter 6: The Traditional Approach to RequirementsBài giảng Systems Analysis and Design in a Changing World - Chapter 6: The Traditional Approach to Requirements

    Summary (continued)  Models from IE may supplement DFDs  Process decomposition diagram (how processes on multiple DFD levels are related)  Process dependency diagram (emphasizes interaction with stored entities)  Location diagram (geographic where system used)  Activity-location matrix (which processes are implemented at which location...

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  • Bài giảng Systems Analysis and Design in a Changing World - Chapter 5: Modeling Systems Requirements: Events and ThingsBài giảng Systems Analysis and Design in a Changing World - Chapter 5: Modeling Systems Requirements: Events and Things

    Summary (continued)  Things are what user deals with and system remembers, such as customer placing an order  Traditional approach uses entity-relationship diagrams (ERD) for data entities, attributes of data entities, and relationships between entities  Things are shown as data entities  Object-oriented approach uses class diagrams for...

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  • Chapter 9 Assertions, Views and Programming TechniquesChapter 9 Assertions, Views and Programming Techniques

    Control structure Example: SELECT ProductID, Quantity, UnitPrice, [discount%]= CASE WHEN Quantity <=5 THEN 0.05 WHEN Quantity BETWEEN 6 and 10 THEN 0.07 WHEN Quantity BETWEEN 11 and 20 THEN 0.09 ELSE 0.1 END FROM [Order Details] ORDER BY Quantity, ProductId

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  • Chapter 8 SQL: Schema Definition, Basic Constraints, and QueriesChapter 8 SQL: Schema Definition, Basic Constraints, and Queries

    Insert, delete, and update The UPDATE Command: to modify attribute values of one or more selected tuples.  a WHERE clause in the UPDATE command selects the tuples to be modified from a single relation.  However, updating a primary key value may propagate to the foreign key values of tuples in other relations if such a referential triggere...

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  • Chapter 7 Relational Database Design by ERand EER-To-Relational MappingChapter 7 Relational Database Design by ERand EER-To-Relational Mapping

    Mapping EER Model Constructs to Relations Step 9: Mapping of Union Types (Categories).  For mapping a category whose defining superclass have different keys, it is customary to specify a new key attribute, called a surrogate key, when creating a relation to correspond to the category.  In the example below we can create a relation OWNER t...

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  • Chapter 6 The Relational Algebra and Relational CalculusChapter 6 The Relational Algebra and Relational Calculus

    Tuple Relational Calculus The tuple relational calculus is based on specifying a number of tuple variables. Each tuple variable usually ranges over a particular database relation, meaning that the variable may take as its value any individual tuple from that relation. A simple tuple relational calculus query is of the form {t | COND(t)} w...

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  • Chapter 5 The Relational Data Model and Relational Database ConstraintsChapter 5 The Relational Data Model and Relational Database Constraints

    In-Class Exercise Consider the following relations for a database that keeps track of student enrollment in courses and the books adopted for each course: STUDENT(SSN, Name, Major, Bdate) COURSE(Course#, Cname, Dept) ENROLL(SSN, Course#, Quarter, Grade) BOOK_ADOPTION(Course#, Quarter, Book_ISBN) TEXT(Book_ISBN, Book_Title, Publisher, ...

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