Question

Is it possible to map an object to only part of an existing table in a database? For example:

public class Account {

    private Integer id;

    private Integer accountNumber;

    @Id
    public Integer getId() {
        return this.id;
    }

    @Column(nullable=false)
    public Integer getAccountNumber() {
        return this.accountNumber;
    }

}

In the database (just for the sake of the question):

 Account

 - id
 - accountnumber

 - lastmodified
 - localbranchid

Answer 1

Yes, you can only map a portion of the columns in the database table to the Account class (you simply just map the columns you are interested in), but if you ever have a need to insert new Accounts into the database and the unmapped columns have not-null constraints and no database default values, you will run into problems.