User:Muffingg/Data Access

OOD	Data Access

JDBC

• ODBC stands for Open Database Connectivity
• JDBC is an API required to communicate to the Database
• Driver allows hardware to communicate to the OS
• java.sql is the package for all JDBC interfaces and classes
• DAO stands for Data Access Object
  • Should be appended to any class that deals with the database
• Entity Class is a class of something that can be a table

Steps for JDBC

1. Register Driver
2. Establish Connection
3. Create Statement
4. Execute Statement

• executeUpdate() : int
• executeQuery() : ResultSet
• execute() : boolean

Java Persistence API (JPA)

• ORM - Object Relational Mapping
  • Connects objects to database tables

• Entity Manager methods:
  • persists fires an insert query
  • merge fires an update query
  • remove fires a delete query

• Relationships in JPA are:
  • @OneToOne
  • @OneToMany
  • @ManyToMany
  • @ManyToMany