Make column foreign and unique at the same time

[kmx]

Hello!
I have XML schema:

Code: Select all

my $XML = qq( 
<TableCreate Name="$t_name">
    <Column Name="id" Required="true" PrimaryKey="true" AutoIncrement="true" Type="BIGINT"/>
    <Column Name="im_id" Required="false" Type="INTEGER"/>
    <Column Name="user_id" Required="false" Type="INTEGER"/>
    <Column Name="customer_user_id" Required="false" Type="INTEGER"/>
    <Column Name="token" Required="false" Size="128" Type="VARCHAR"/>
    <Column Name="valid" Required="true" Type="SMALLINT"/>
    <Column Name="activation_time" Required="false" Type="DATE"/>
    <Unique Name="im_id">
        <UniqueColumn Name="im_id"/>
    </Unique>
    <Unique Name="token">
        <UniqueColumn Name="token"/>
    </Unique>
    <ForeignKey ForeignTable="users">
        <Reference Local="user_id" Foreign="id"/>
    </ForeignKey>
    <ForeignKey ForeignTable="customer_users">
        <Reference Local="customer_user_id" Foreign="id"/>
    </ForeignKey>
</TableCreate>
);

How can I set my customer_user_id column both foreign and unique?
I'm using otrs4 with oracle-xe-11g.
Sorry for my runglish