Urgent help needed:

rc · **Joined:** Tue Sep 16, 2003 4:45 pm **Posts:** 14

Hi
I am getting the following error on compiling the program

net.sf.hibernate.MappingException: Dialect does not support native key generation

The configuration of hibernate.properties file is given below
---------------------------------------------------------------
hibernate.dialect net.sf.hibernate.dialect.MySQLDialect
hibernate.connection.driver_class org.gjt.mm.mysql.Driver
#hibernate.connection.driver_class com.mysql.jdbc.Driver
hibernate.connection.url jdbc:mysql://localhost:3306/testdb
hibernate.connection.username root
hibernate.connection.password abx01
-----------------------------------------------
The configuration of the entity file is given below
------------------------------------------------
<class name="eg.entity.Merchant"
table="Merchant">

<id name="merchantid"
column="merchantid"
unsaved-value="-1">
<generator class="identity"/>
</id>

<property name="merchantname"
column="merchantname"
not-null="true"
unique="true"
/>
<property name="merchantwebsite"
column="merchantwebsite"
not-null="false"
unique="false"
/>

</class>
---------------------------------------------------------
Thanks in advance for all the replies.

max · **Posted:** Wed Sep 17, 2003 4:07 pm

rc wrote:

Hi
I am getting the following error on compiling the program

net.sf.hibernate.MappingException: Dialect does not support native key generation

eh - the error is standing right there in the exception!
The dialect you have chosen (MySql) does not support native key generation - use another database or change key generation strategy ,)

/max

svaret · **Posted:** Wed Dec 10, 2003 7:02 pm

Hi there,

I have got the same problem as stated above. What surprises me a bit is that u say it is not supported for MySQL dialect. In chapter 5.1.4.1 of the hibernate reference, http://www.hibernate.org/hib_docs/reference/html/or-mapping.html,
says it is.

identity
supports identity columns in DB2, MySQL, MS SQL Server, Sybase and HypersonicSQL. The returned identifier is of type long, short or int.

What am I missing here?

Best regards
Lasse

gavin · **Posted:** Wed Dec 10, 2003 7:09 pm

Max is mistaken. MySQL supports identity/native ids. More likely your properties file is not being found.

svaret · **Posted:** Thu Dec 11, 2003 3:49 am

gavin wrote:

Max is mistaken. MySQL supports identity/native ids. More likely your properties file is not being found.

my mapping file looks like this:
--------------------------------------------------------------------------------

Code:

<hibernate-mapping>

    <class name="Cat" table="CAT">

    <id name="id" type="long" column="CAT_ID" unsaved-value="0">
        <generator class="identity"/>
    </id>

        <!-- A cat has to have a name, but it shouldn' be too long. -->
        <property name="name">
            <column name="NAME" sql-type="varchar(16)" not-null="true"/>
        </property>

        <property name="sex"/>

        <property name="weight"/>

    </class>

</hibernate-mapping>

my properties file looks like this
-------------------------------------

Code:

<hibernate-configuration>

    <session-factory>

        <property name="connection.datasource">java:/MySqlDS</property>
        <property name="show_sql">false</property>
        <property name="dialect">hibernate.dialect net.sf.hibernate.dialect.MySQLDialect</property>

        <!-- Mapping files -->
        <mapping resource="Cat.hbm.xml"/>

    </session-factory>

</hibernate-configuration>

You suggested that the properties file (in my case hibernate.cfg.xml) could not be found. However, when I rename or remove the config file I get
HTTP ERROR: 500 /hibernate.cfg.xml not found

So, finding the config file was not the problem. I am really struggling with this. It feels like this should be a fairly common problem since I am not doing anything complicated.

By the way, I got it working with
generator class="uuid.hex" ... the problem is that I have already started with auto_incremented ids in my tables so I really would like to continue on that path, which I should be able to with generator="identity".

Best regards

Lasse
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gavin · **Posted:** Thu Dec 11, 2003 4:01 am

Well, the problem is pretty obvious:

Code:

<property name="dialect">hibernate.dialect net.sf.hibernate.dialect.MySQLDialect</property> 

clearly should be:

<property name="dialect">net.sf.hibernate.dialect.MySQLDialect</property>

svaret · **Posted:** Thu Dec 11, 2003 5:32 am

It worked. Thanx a looooooooot ... The mistake I made was to copy the dialect part directly from the properties file.

Best regards

Lasse