Hibernate is an implementation of the jpa specification is an open source object-relational mapping framework, Hibernate to lightweight JDBC object encapsulation, the POJO establish the mapping relationship with a database table, is a fully automatic ORM framework;
ORM thought: objective: through the operating entity class object to CRUD operations on the database, no longer focused on SQL statements,
Core configuration file: meta-inf \ persistence XML
Main configuration from three aspects, 1. Jpa implementation approach, 2. Database information, 3. The implementation of configuration information (optional configuration)
Entity class comments:
@ the Entity declaration such as Entity class
@ Table, the value of the name attribute for the associated database Table name
@ primary key Id statement
@ the Column set up entity class attribute and the database field mapping
@ GenernatedValue allocation of primary key generation strategy