Where to define the sequence to be used on generator class?

emylonas · **Joined:** Thu Aug 04, 2005 2:24 pm **Posts:** 45

Need help with Hibernate? Read this first:
http://www.hibernate.org/ForumMailingli ... AskForHelp

Hibernate version:

Mapping documents:

Code between sessionFactory.openSession() and session.close():

Full stack trace of any exception that occurs:

Name and version of the database you are using:

The generated SQL (show_sql=true):

Debug level Hibernate log excerpt:

Before Hibernate, i was used to having a PK attached to a sequence by a trigger (Oracle). This way i never had to deal with my PKs generation.

But now Hibernate has this "generator" thing. I understand that if i use "assigned" i will have to deal with the PK generation on the application end.

Now there's this "sequence" as the generator, but i can't find the tag to define the sequence's name (<seqname>somesequence</seqname>). Is it automatically created by Hibernate on the database?

Thanks

marco-p · **Posted:** Tue Oct 11, 2005 10:53 am

No, the sequence must be created on the db. I suggest to disable the trigger then, or the id generated by hibernate will be replaced by the one from the trigger

emylonas · **Joined:** Thu Aug 04, 2005 2:24 pm **Posts:** 45

But if the sequence has to be created on the db, which i thought it had to, how does hibernate know the sequence to be used if i don't have the tag?

This is what i have:
<id name="assemblyNum" type="long">
<column name="ASSEMBLY_NUM" precision="10" scale="0"/>
<generator class="sequence"/>
</id>

I couldn't find a way to place the sequence name yet...

Thanks a lot

matthewramella · **Posted:** Tue Oct 11, 2005 1:58 pm

In Oracle, can you set the Primary Key field to auto-incrment? I use this option in MySQL and then use the following in my hbm doc:

Code:

Hibernate then automatically receives the next ID from the database upon record insert.

You might be able to keep your trigger in place and simply use the "select" option... Haven't tried this yet in Oracle, so I can't be sure...

kochcp · **Posted:** Tue Oct 11, 2005 2:33 pm

Code:

    <id
        name="intSeqNo"
        type="java.lang.Integer"
        column="int_seq_no"
    >
        <generator class="native">
            <param name="sequence">name_of_db_sequence_goes_here</param>
        </generator>
    </id>

I think this is what you're looking for

emylonas · **Joined:** Thu Aug 04, 2005 2:24 pm **Posts:** 45

matthewramella wrote:

In Oracle, can you set the Primary Key field to auto-incrment? I use this option in MySQL and then use the following in my hbm doc:

Code:

Hibernate then automatically receives the next ID from the database upon record insert.

You might be able to keep your trigger in place and simply use the "select" option... Haven't tried this yet in Oracle, so I can't be sure...

Well, Oracle doesn't support auto-increment, which sucks...

But thanks for the tip...

emylonas · **Joined:** Thu Aug 04, 2005 2:24 pm **Posts:** 45

kochcp wrote:

Code:

    <id
        name="intSeqNo"
        type="java.lang.Integer"
        column="int_seq_no"
    >
        <generator class="native">
            <param name="sequence">name_of_db_sequence_goes_here</param>
        </generator>
    </id>

I think this is what you're looking for

Hummm... this looks good!!!

I understand 'native' uses 'identity', 'sequence' or 'hilo' depending on the underlying database... so i figure that if i have this setting, but instead of Oracle i try to connect to SQL Server, for example, it hibernate will pick up the identity fields automatically...?

Thanks a whole lot (Y)

kochcp · **Posted:** Tue Oct 11, 2005 2:58 pm

Quote:

but instead of Oracle i try to connect to SQL Server, for example, it hibernate will pick up the identity fields automatically

yep. this works on all three of my test databses: sql server, oracle, and for some reason we are still testing on db2