I Relational Database Modeling-how to define Relational Model data structure,operations,constraints Design theory for relational database High-level Models E/R model,UML model,ODL
I Relational Database Modeling – how to define Relational Model • data structure, operations, constraints • Design theory for relational database High-level Models • E/R model, UML model, ODL
II Relational Database Programming how to operate From an abstract point of view to study the question of database queries and modifications.(chapter 5) ■ Relational Algebra ■A Logic for relation From a practical point to learn the operations on Database The Database Language SQL (chapter 6~10)
II Relational Database Programming – how to operate From an abstract point of view to study the question of database queries and modifications. (chapter 5) Relational Algebra A Logic for relation From a practical point to learn the operations on Database The Database Language SQL (chapter 6~10)
Chapter 5 Algebraic and Logic Query languages Relational operations (chapter 2) Extended operators Datalog:a logic for relations Relational algebra and Datalog
Chapter 5 Algebraic and Logic Query languages Relational operations (chapter 2) Extended operators Datalog: a logic for relations Relational algebra and Datalog
Review 1:what is Relational Algebra? An algebra whose operands are relations or variables that represent relations. Operators are designed to do the most common things that we need to do with relations in a database. The result is an algebra that can be used as a query language for relations
Review 1: what is Relational Algebra? An algebra whose operands are relations or variables that represent relations. Operators are designed to do the most common things that we need to do with relations in a database. The result is an algebra that can be used as a query language for relations
Review 2: of Relational Algebra Set operations:Union,intersection and difference (the relation schemas must be the same) ■ Selection:Picking certain rows from a a relation. Projection:picking certain columns. Products and joins:composing relations in a useful ways. ■ Renaming of relations and their attributes
Review 2: “Core” of Relational Algebra Set operations: Union, intersection and difference (the relation schemas must be the same) Selection: Picking certain rows from a relation. Projection: picking certain columns. Products and joins: composing relations in a useful ways. Renaming of relations and their attributes