Week10_Chap12&13 User Interface and Persistence&Database

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,10/30/2013,#,Chapter 12,Application Design II:The User Interface,12-,2,12-,3,The User Interface,User interface is the area of interaction between an application and its,human,users.,User interface is where the problem domain and the solution domain meet and interact.,12-,4,The Responsibilities of the User Interface,The user interface is responsible for:,accepting and editing user input.,producing human-intelligible output.,guiding users to accomplish tasks.,12-,5,12-,6,12-,7,12-,8,Navigation,Navigation specifies the sequence of user actions across multiple containers to achieve a goal.,12-,9,Chapter 13,Application Design III:Database & Persistence,13-,11,13-,12,The Database,A database is an organized collection of data.,A data management system must be able to carry out the following operations:,Create,: accept new data and create entries in the database.,Retrieve,: find and read the data that the information system and its users require.,Update,: allow existing data to be changed.,Delete,:,permit unneeded data to be removed,.,These four operations are often referred to as,CRUD,:,C,reate,R,etrieve,U,pdate and,D,elete.,13-,13,The Database Management System (DBMS),Database management systems are products that encapsulate and carry out the responsibilities of data management.,13-,14,The Relational Database Management System (RDBMS),The relational model,presents a logical view of the database organization and provides the basis for using a high-level language for database management.,13-,15,The Relational Model,A table is the basic organizational unit of a relational database.,A table is a rectangular arrangement of data, composed of columns and rows. A column is also referred to as an,attribute, a row as a,tuple, and their intersection as a,cell,.,13-,16,13-,17,A view is a virtual table that represents a selected set of attributes from one or more tables,13-,18,A stored procedure is a named set of SQL statements that provides the capability of performing database-related tasks from within the database itself.,13-,19,Data Normalization,Normalization is the process of establishing an optimal table structure based on the internal data dependencies.,13-,20,Denormalization,Denormalization might become necessary due to logical considerations, technological constraints and performance degradation.,13-,21,Mapping to Relational Databases,Mapping to a relational database is the application of relational and normalization rules to classes and their relationships.,13-,22,Designing Persistence,Classes.,Entity classes form the overwhelming majority of tables.,Attributes,Class attributes become table attributes (or columns.),The Primary Key,A table must have a primary key.,Repeating Attributes,Repeating attributes must be separated into tables.,Associations,Associations are mapped by a primary-foreign key pairs.,Multiplicity,Multiplicity is mapped through foreign keys.,Aggregation,To map to a relational database, aggregation must be flattened into association.,