I am trying to run the example from hibernate reference. I am using Hibernate 3.1 and MySql server 5.0. The class to be stored is the following:

public class Event {
private Long id;
private String title;
private Date date;
...setters and getters
}

the mapping file is the following:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

<class name="events.Event" table="events">
<id name="id" column="EVENT_ID">
<generator class="native"/>
</id>
<property name="date" type="timestamp" column="EVENT_DATE"/>
<property name="title"/>

</class>


</hibernate-mapping>

In Msql:
EVENT_ID is a BIGINT
DATE is a DATE
TITLe a varchar;

When I am trying to insert a new Event in the table, The following error occurs:
5:16:11,381 DEBUG SQL:346 - insert into events (EVENT_DATE, title) values (?, ?)
15:16:11,461 WARN JDBCExceptionReporter:71 - SQL Error: 1364, SQLState: HY000
15:16:11,461 ERROR JDBCExceptionReporter:72 - Field 'EVENT_ID' doesn't have a default value



However if I change the type of the EVENT_ID column to varchar and the java type of id to string and i use the generator class "uuid.hex" all insertion is done smoothly.
Does anyone know what is the problem

Thanks!
Eduard

Eduard,
Try the folowing

public class Event {
private int id;
private String title;
private Date date;
...setters and getters
}

the mapping file is the following:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

<class name="events.Event" table="events">
<id name="id" column="EVENT_ID" type="int">
<generator class="native"/>
</id>
<property name="date" type="timestamp" column="EVENT_DATE"/>
<property name="title"/>

</class>


</hibernate-mapping>

Well, meanwhile I solved the problem by setting the generator class to increment. The native generator does not work!

Regards!
Eduard

I think you need to read the docs about exactly what specifying "native" does. It's not type of generator in itself, it just defaults to one of several depending on the DB being used. You still need to configure those properly.


native - picks identity, sequence or hilo depending on the underlying capabilities of the database.


MySQL supports identity columns but you have to have your table defined properly.

I don't think it supports sequences and the hilo generator requires additional configuration in your mapping.

Well, you are right. I also notice this but afterwards. However the documentation is a little bit misleading! When the example is posted it is written:

"The nested generator element specifies the
identifier generation strategy, in this case we used native, which picks the best strategy depending on the configured database (dialect)."

Which made me think that this generator abstsracts away the user from how the identifier is generated (but it guaranties in the same time the uniqness of the identifier).
For my application however the "increment " is ok!

Thanks!
Eduard