initialize default value in default constructor?

imsardine · **Joined:** Wed Nov 02, 2005 10:49 pm **Posts:** 12

Hibernate Reference Documentation 20.1.1. Customizing the schema says that:

Quote:

The default attribute lets you specify a default value for a column (you should assign the same value to the mapped property before saving a new instance of the mapped class).

Code:

<property name="credits" type="integer" insert="false">
    <column name="credits" default="10"/>
</property>

[/quote]

What "you should assign the same value to the mapped property before saving a new instance of the mapped class" means? does it means that the default attribute only applied to hbm2ddl tool?

If that's right, how can I initialize property's default value, especially for String field, because of underlying DB's NOT NULL contraint?

Is it possible to this job in POJO default constructor? sometimes I got the following erros:

Code:

public class ScheduleItem {
    private Integer mId;
    private String consignee;
    private String consigneePhone;
    ...
    
    public ScheduleItem() {
        consignee = "";
        consigneePhone = "";
        oldFurnitureMoveTo = "";
        mOtherNote = "";
        mOtherNote2 = "";
        mOtherNote3 = "";
        mConfirmLog = "";
    }
    ...
}

org.hibernate.AssertionFailure: null id in ScheduleItem entry (don't flush the Session after an exception occurs)

Could anybody do me a favor? thank you.

batmat · **Posted:** Sat Dec 30, 2006 11:15 am

I guess yes. There are a lot of properties that are only aimed at schema generation (foreign-key attribute, <comment>, length, not-null, and so on).

However it's not necessary to init every string to "". It's more useful for a default age, for example. But defaulting empty string is certainly unuseful I think, because for example Oracle considers null and empty strings as equivalent, I seem to remember.