Java Objects and Database Records

[David Garratt]

Can anyone suggest suitable reading material to guide me in designing class's which specifically map to database tables and provide a "standard" approach to record manipulation. For example I find myself unsure as to the best practice for creating a new record in a table. Do I create a new instance of an object, passing the primary key to the constructor and allow the constructor to create a matching record OR do I create new object, set various fields and then call a method call .Create or .Insert

I'm happy with the mechanics of JDBC - I just need some advice as to best practice if indeed there is an agreed best way of doing this.

Dave

[Preetham Chandrasekhar]

Hi,
Since you are using java objects and would like to create records in the database, I prefer using Object-Relational mapping tools like Hibernate. This is a suggestion because it makes things a lot easier where primary keys are automatically generated (object ids). However it is really slow when compared to jdbc.
http://www.hibernate.org/

[Layne Lund]

I recently asked a similar question recently because I was working on a Swing application that needed to connect to a database. Perhaps the suggestion made there will help.

Layne
[ July 14, 2005: Message edited by: Layne Lund ]

[Jacquie Barker]

When designing an application with persistent storage, it's important to strive for model - data layer separation. That is, rather than embedding JDBC code into the constructor for a model object, e.g.

// Take 1 -- wrong approach.
public class Person {
    private String id;
    private String name;
    // etc.
 
    public Person(String id) {
        // Pseudocode.
        use JDBC calls to look up the id in the Person table ...
    }
}

it's better to have a separate class(es) that provide database access and "serve" Person objects to the application:

public class DataAccess {
    public static Person getPerson(String id) 
        throws InvalidPersonException {
        // Pseudocode.
        use JDBC calls to look up the id in the Person table,
        construct a person, and return it
    }
}

I have an entire example of this in Chapter 15 of B.J.O. ... drop me an email ([e-mail]) and I'll elaborate.

Regards,

Jacquie