Organizing Dao data

In the past two days, due to the use of DAO technology, I learned and studied it. Updating...

Let's talk about the environment first.

Ecplise3.2, jdk1.5, hibernate3.0

Dao is automatically generated. (select a table in dB Brower to generate a hibernate table ing. Select the DaO column)

Then we can see that each table in the created package has three files (such as user, permission, and user permission relation table)

Example of a user: User. Java abstractuser. Java userdao. Java

A typical Dao composition: Dao factory class, Dao interface, specific class implementing Dao interface (each DAO instance is responsible for a main domain object or entity), VO (value object ).

If only one Dao factory is considered as a database implementation, the factory design mode is used when many Dao are created.