Hi, I found a lot people has post topic about this error, but can't find one that is similar to mine.

I'm using Hibernate 2.1.1, MS SQL Server 2000 with driver from data direct.

I have one simple table "boss" with no reference.
It have 2 fields :
- id bigint (pk)
- name varchar 70

This is the mapping:
<class name="Boss" table="boss">
<id name="id" type="long" unsaved-value="null">
<generator class="identity"/>
</id>
<property name="name" type="string"/>
</class>

The bean class :
public class Boss
{
private Long id;
private String name;

public Long getId() {
return id;
}

public void setId (Long _id) {
id = _id;
}

public String getName() {
return name;
}

public void setName (String _name) {
name = _name;
}
}

And this is the code that save the object :
Transaction tx = sess.beginTransaction();
Boss b = new Boss();
b.setName("Mr. Tong Ki Cai");
sess.save(b); //error on this line

This is the error :
Cannot insert the value NULL into column 'id', table 'metro.dbo.boss'; column does not allow nulls. INSERT fails.

Susilo

Looks to me like you did not specify the id column to be autgenerated by the database. Don't know how to do this in SQLServer though.

I only set "id" to be primary key, not auto-generated key. Do I have to? I thought the value will come from Hibernate, not the database.

If that's the problem, I can't find how to set it to auto-generated. Anyone know how? I'm using MS SQL Server 2000.

Well, identity generator means the ID gets assigned by the database. Use something like increment or uuid if you want hibernate to assign the id.

The Syntax for identity should be something like this:



Google is your friend.

Yes, you're right!
I've managed to fix it.
Thanks a lot, man!
I've spent too long on this error.

Can I ask one last question?
In the documentation, it said this about using increment : "unique only when no other process is inserting data into the same table"
What other process do they mean? Multi-Thread in Java? Manual insert to the table?

Any other process inserting data in the same table which does not use this increment generator I suppose. This might be another application, or some java stuff running in a different VM (cluster for example)

Hi, I was facing the same issue, only I cannot simply decide to redefine the db tables, since they are not "mine" to change. The docs say that using a "native" generator should select most suitable approach for the dbms I'm working with, so:
Assuming the table only has a primary key (without any special dmsb-side id generation settings), can Hibernate help me auto-generate id's (needless to say, "native" didn't work and gave the exception in the first place)?