Any mapping element which accepts a column attribute will alternatively accept a <column> subelement. Likewise, <formula> is an alternative to the formula attribute.

<column
        name="column_name"
        length="N"
        precision="N"
        scale="N"
        not-null="true|false"
        unique="true|false"
        unique-key="multicolumn_unique_key_name"
        index="index_name"
        sql-type="sql_type_name"
        check="SQL expression"
        default="SQL expression"/>

<formula>SQL expression</formula>

column and formula attributes may even be combined within the same property or association mapping to express, for example, exotic join conditions.

<many-to-one name="homeAddress" class="Address"
        insert="false" update="false">
    <column name="person_id" not-null="true" length="10"/>
    <formula>'MAILING'</formula>
</many-to-one>