ITEC 4020 - L3: UML & Data Persistence

Structural Model

A representation of classes, attributes, and relationships that maps real-world concepts into software.

Class Diagram

UML diagram showing classes, attributes, operations, and relationships; maps to database tables and keys.

Class to Table Mapping

In UML to DB mapping: classes become tables, attributes become columns, and associations become foreign keys.

Inheritance Mapping

Database strategies for representing class inheritance, such as single-table or multiple-table mapping.

Data Persistence

The concept of storing program data in files or databases for long-term access.

Relational Database

Database system organized into tables of rows and columns, accessed using SQL.

Primary Key

A unique identifier for each record in a table.

Foreign Key

A field in one table that refers to the primary key of another table to establish relationships.

Referential Integrity

Ensures foreign key values always correspond to existing primary key values.

Indexing

Creating a lookup structure to speed up queries at the cost of additional storage and overhead.

SQL SELECT

Retrieves data from a table.

SQL INSERT

Adds new data into a table.

SQL UPDATE

Modifies existing records in a table.

SQL DELETE

Removes records from a table.

SQL JOIN

Combines rows from two or more tables based on related columns.

JDBC

Java API for connecting and executing queries with a database.

JDBC Workflow

Steps: load driver, connect, create statement, execute query/update, process ResultSet, close connection.

ResultSet

Java object representing rows returned by a SQL query, traversed with next().

MVC Architecture

Design pattern dividing software into Model (logic/data), View (UI), and Controller (request handling).

Model in MVC

JavaBeans that store data and business logic, interacting with the database.

View in MVC

JSP pages that handle presentation and user interface.

Controller in MVC

Servlets that handle client requests, call the model, and forward to views.

Normalization

Process of structuring a database to reduce redundancy and improve integrity.

1NF (First Normal Form)

Each column holds atomic values, no repeating groups or arrays.

2NF (Second Normal Form)

Each table describes one entity, and all non-key attributes depend on the entire primary key.

3NF (Third Normal Form)

All non-key attributes depend only on the key and not on other non-key attributes.

Denormalization

Introducing redundancy into a database design to improve performance.

Bean

Reusable Java object with fields and getter/setter methods, often used as a model in MVC.

Case Study – Online Community

Example system requiring content storage, collaboration, moderation, and search, with workflows for submissions.

Workflow

A sequence of states or tasks (e.g., submitted → approved → published) managed by the system.