how can I set default value of one column in x.hbm.xml file?

sojan · **Joined:** Tue Sep 02, 2003 10:28 pm **Posts:** 11

this is the main part of my xxx.hbm.xml file:

<hibernate-mapping>
<class name="com.animal.Clob" table="ANIMAL_CLOB">
<id name="id" column="ID" type="long" unsaved-value="null">
<generator class="hilo"/>
</id>
<property name="clob" column="CLOB" type="string" not-null="true"/>

<property name="createDate" column="CREATE_DATE" type="date" default="SYSDATE"/>
<property name="status" column="STATUS" type="integer" length="1" not-null="true"/>
</class>
</hibernate-mapping>

default="SYSDATE" is just where i need to set the default value of the column: CREATE_DATE.
i try it, BUT SAXParseException has been thrown while parsing this xml.
it seem that default can not be identified.

please tell me how can i do it?

david · **Posted:** Wed Sep 03, 2003 2:57 am

It looks like you are using Oracle. There is no way it would know that sysdate as a function for the default value. I suggest you manage this at the domain model level and set the field on construction of the domain object to todays date, eg, _createDate = new Date();

Another option is to place this into an interceptor which will get it closer to the actual time it hit the database (differnece would be minimal), or I supoose you could implement the net.sf.hibernate.Validatable interface on the domain object and check if it valid if not new Date().

gavin · **Posted:** Wed Sep 03, 2003 5:48 am

There is no default attribute in Hibernate mappings.

If you want to do this use a trigger.

sojan · **Joined:** Tue Sep 02, 2003 10:28 pm **Posts:** 11

thank you for you replay, and your endless patience!

kutzi · **Posted:** Tue Aug 31, 2004 5:16 am

@david: What about using the Lifecycle interfaces onSave method for default values?

@gavin: But when I have a not-null column i cannot use database triggers to fill the field, because hibernate complains that the field is empty!

yuvraj · **Joined:** Wed Feb 28, 2007 2:43 am **Posts:** 1

is this expected any time soon at all ?

DarthMambo · **Joined:** Mon Feb 19, 2007 5:10 am **Posts:** 15

My workaround and issue...

The Task
I recently worked on an object which represents an uploaded file. We wanted this object to have an uploadDateTime field to store the date at which the record was created.

The Solution
I got this to work by setting up the database DDL thus:

Code:

updateDateTime DateTime NOT NULL DEFAULT GETDATE()

I updated the NHibernate mapping for that column:

Code:

<property column="uploadDateTime" type="DateTime" name="UploadDateTime" not-null="true" insert="false" update="false"

The insert="false" update="false" prevents NHibernate from using that field in INSERT and UPDATE statements, thereby forcing the database to generate the default value.

I wrote a unit test that saved down the object and then queried the database for that object and found that the uploadDateTime field had been populated. Success!

However...

The Problem
I noticed that upon saving a object, the property isn't automatically populated. This is because, although the record is created in the database and the field is populated, the field value is not then synchronised back up with the object!

The Workaround
I'm going to populate this field in my DAO layer before insertion.

The Feature Request
Couldn't NHibernate recognise that it would need to synchronise the field after insertion upon seeing the following combination of column attributes?

insert="false"
not-null="true"

ajaygautam · **Joined:** Wed May 24, 2006 4:40 pm **Posts:** 10

I had something similar setup... with the database setting default values.

The scheme breaks down when hibernate settings contain:

Code:

hibernate.hbm2ddl.auto=create

This recreates the database with the defaults missing.

Do you have an alternate way to get default values working?

Right now, I am trying to find a solution along this line:
Maybe there is a way to execute a set of sql statements right after hibernate recreates the database. I have the sql to set the default values back.

Any idea how I could achieve this ?

Thanks

Ajay

ajaygautam · **Joined:** Wed May 24, 2006 4:40 pm **Posts:** 10

Ok. So I fixed it with the following (yet another) workaround.

In my case, hibernate.hbm2ddl.auto=create is set in junit so, in setUp(), I added a call to:

Code:

...
session.createSQLQuery("alter table MDI_REFDATA modify LME_IGNORE_CASH tinyint default 0 not null").executeUpdate();
session.createSQLQuery("alter table MDI_REFDATA modify MARKET_CENTER_TYPE tinyint default 0 not null").executeUpdate();
session.createSQLQuery("alter table MDI_REFDATA modify BASE_SERIES_ID tinyint default 0 not null").executeUpdate();
...

So, basically junit process fixes this now...

If anyone knows a better way, I am all ears...

Ajay

redyz · **Joined:** Wed Aug 25, 2010 2:06 pm **Posts:** 4

I updated the NHibernate mapping for that column:

Code:
<property column="uploadDateTime" type="DateTime" name="UploadDateTime" not-null="true" insert="false" update="false"

The insert="false" update="false" prevents NHibernate from using that field in INSERT and UPDATE statements, thereby forcing the database to generate the default value.

Has anyone tried insert="false" update="false" with an id element?
I get this error:
Multiple annotations found at this line:
- Attribute "update" must be declared for element type "id".
- Attribute "insert" must be declared for element type "id".

It only seems fine with a property element.

I am trying the same thing which is to force the (Oracle) database to generate the default value which is a timestamp.