using Oracle sequence in composite id

bratek · **Joined:** Mon Jan 23, 2006 12:01 pm **Posts:** 46

Hello,

I'm using Hibernate 3.1. After importing a db schema from Oracle I got, among others, this mapping:

<composite-id name="id" class="hibernate.mypackage.MyTestId">
<key-property name="mainId" type="long">
<column name="MAIN_ID" precision="10" scale="0" />
</key-property>
<key-property name="effectiveDate" type="timestamp">
<column name="EFFECTIVE_DATE" length="7" />
</key-property>
<key-property name="periodType" type="string">
<column name="PERIOD_TYPE" length="20" />
</key-property>
</composite-id>

An additional Java class was created for the composite key (MyTestId). The class created for the actual table was MyTest.
Now one of those columns (MAIN_ID) had a sequence generator created for it (SEQ_MAIN_ID). My question is: is it possible to modify the mapping somehow to tell Hibernate that SEQ_MAIN_ID should be used for creating the MAIN_ID column values?

I'd appreciate any help on the subject.
Thanks,

Marcin Bratek

kochcp · **Posted:** Mon Jan 23, 2006 12:21 pm

Code:

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

bratek · **Joined:** Mon Jan 23, 2006 12:01 pm **Posts:** 46

Does that mean that I can either have a sequence-generated id, or a composite key, but not both? It kind of makes sense, since sequence provides unique values, but still?

kochcp · **Posted:** Mon Jan 23, 2006 2:49 pm

bratek wrote:

Does that mean that I can either have a sequence-generated id, or a composite key, but not both? It kind of makes sense, since sequence provides unique values, but still?

I see no reason for a composite id that includes a generated key. You're welcome to try it, but I think the hibernate developers agree with me as hibernate just seems to work better with surrogate keys. (compared against natural keys)