<?xml version="1.0" encoding="UTF-8"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
                  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                  xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping
                  http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">

    <mapped-superclass name="ZfcUser\Entity\User" table="user">

        <id name="id" type="integer" column="user_id">
            <generator strategy="AUTO" />
        </id>

        <field name="username" type="string" length="255" unique="true" nullable="true" />
        <field name="email" type="string" unique="true" length="255" nullable="true"/>
        <field name="displayName" column="display_name" type="string" length="50" nullable="true" />
        <field name="password" type="string" length="128" />
        <field name="state" type="smallint" />

    </mapped-superclass>

</doctrine-mapping>

<?xml version="1.0" encoding="UTF-8"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
                  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                  xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping
                  http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">

    <mapped-superclass name="ZfcUser\Entity\User" table="user">

        <id name="id" type="integer" column="user_id">
            <generator strategy="AUTO" />
        </id>

        <field name="username" type="string" length="255" unique="true" nullable="true" />
        <field name="email" type="string" unique="true" length="255" nullable="true"/>
        <field name="displayName" column="display_name" type="string" length="50" nullable="true" />
        <field name="password" type="string" length="128" />
        <field name="state" type="smallint" nullable="true" />

    </mapped-superclass>

</doctrine-mapping>

Allow state to be nullable like ZfcUser's schema.
Allow state to be nullable like ZfcUser's schema.