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Can I re-use one column from comp-id into a unique-index ?

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bruno.melo

Post subject: Can I re-use one column from comp-id into a unique-index ?

Posted: Sun Oct 05, 2008 3:11 pm

Newbie

Joined: Mon Feb 25, 2008 11:49 pm
Posts: 6

Hibernate version:
Hibernate-Version: 3.1.3

Mapping documents:

+ This is the mapping for a USER table

Code:

    <composite-id name="comp_id" class="UserPK">
        <key-property
            name="quarter" 
            column="QUARTER" 
            type="java.lang.String"
            length="7"
        />
        <key-property 
            name="userId" 
            column="USER_ID" 
            type="java.lang.String"
            length="12"
        />
    </composite-id>
    ....
    <property
        name="login"
        type="java.lang.String"
        column="USER_LOGIN"
        not-null="true"
        length="80"
    />

My question is :

Can I create a mapping to generate a unique constraint with the QUARTER and USER_LOGIN fields ?

So that the table DDL would look like :

Code:

create table USER (QUARTER varchar(7) not null, USER_ID varchar(12) not null, USER_LOGIN varchar(80) not null, primary key (QUARTER, USER_ID), unique (QUARTER, USER_LOGIN))

I tried using unique-key and natural-index but I got an error saying that the QUARTER column was duplicate.

Thank you.

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bruno.melo

Post subject:

Posted: Mon Oct 06, 2008 4:10 pm

Newbie

Joined: Mon Feb 25, 2008 11:49 pm
Posts: 6

I found a partial solution to this problem, where is what I did so far :

Added a many-to-one association pointing to the same table :

Code:

    <many-to-one
        name="ak1UserLogin"
        class="UserHB"
        insert="false"
        update="false"
        unique-key="login"
    >
        <column name="QUARTER" />
        <column name="USER_LOGIN" />
    </many-to-one>

This mapping generates the following DDL :

Code:

create table USER (QUARTER varchar(7) not null, USER_ID varchar(12) not null, USER_LOGIN varchar(80) not null, primary key (QUARTER, USER_ID), unique (QUARTER, USER_LOGIN))

So far so good, but the catch is that now it's also generating this alter table :

Code:

alter table USER add constraint FKEF82875CB55E62BC foreign key (QUARTER, USER_LOGIN) references USER

So it's creating a constraint pointing to QUARTER/USER_ID with QUARTER/USER_LOGIN which just locks the table completely :)

Anyway, it's a progress.

Anyone have any other idea ?

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