Java JDBC and ORM element entity-mappings

Abstract	false (This can be used in an instance)
Nillable	false (Instance values cannot use xsi:nil)
Target Namespace	http://java.sun.com/xml/ns/persistence/orm
Declared Namespaces	xmlns:orm=http://java.sun.com/xml/ns/persistence/orm xmlns:xsd=http://www.w3.org/2001/XMLSchema

<xsd:element name="entity-mappings">
    <xsd:complexType>
        <xsd:annotation>
            <xsd:documentation>
The entity-mappings element is the root element of an mapping
file. It contains the following four types of elements:

1. The persistence-unit-metadata element contains metadata
for the entire persistence unit. It is undefined if this element
occurs in multiple mapping files within the same persistence unit.

2. The package, schema, catalog and access elements apply to all of
the entity, mapped-superclass and embeddable elements defined in
the same file in which they occur.

3. The sequence-generator, table-generator, named-query,
named-native-query and sql-result-set-mapping elements are global
to the persistence unit. It is undefined to have more than one
sequence-generator or table-generator of the same name in the same
or different mapping files in a persistence unit. It is also
undefined to have more than one named-query or named-native-query
of the same name in the same or different mapping files in a
persistence unit.

4. The entity, mapped-superclass and embeddable elements each define
the mapping information for a managed persistent class. The mapping
information contained in these elements may be complete or it may
be partial.
            </xsd:documentation>
        </xsd:annotation>
        <xsd:sequence>
            <xsd:element name="description" type="xsd:string" minOccurs="0"/>
            <xsd:element name="persistence-unit-metadata" type="orm:persistence-unit-metadata"
                minOccurs="0"/>
            <xsd:element name="package" type="xsd:string" minOccurs="0"/>
            <xsd:element name="schema" type="xsd:string" minOccurs="0"/>
            <xsd:element name="catalog" type="xsd:string" minOccurs="0"/>
            <xsd:element name="access" type="orm:access-type" minOccurs="0"/>
            <xsd:element name="sequence-generator" type="orm:sequence-generator" minOccurs="0"
                maxOccurs="unbounded"/>
            <xsd:element name="table-generator" type="orm:table-generator" minOccurs="0"
                maxOccurs="unbounded"/>
            <xsd:element name="named-query" type="orm:named-query" minOccurs="0"
                maxOccurs="unbounded"/>
            <xsd:element name="named-native-query" type="orm:named-native-query" minOccurs="0"
                maxOccurs="unbounded"/>
            <xsd:element name="sql-result-set-mapping" type="orm:sql-result-set-mapping"
                minOccurs="0" maxOccurs="unbounded"/>
            <xsd:element name="mapped-superclass" type="orm:mapped-superclass" minOccurs="0"
                maxOccurs="unbounded"/>
            <xsd:element name="entity" type="orm:entity" minOccurs="0" maxOccurs="unbounded"/>
            <xsd:element name="embeddable" type="orm:embeddable" minOccurs="0" maxOccurs="unbounded"/>
        </xsd:sequence>
        <xsd:attribute name="version" type="orm:versionType" fixed="1.0" use="required"/>
    </xsd:complexType>
</xsd:element>

element {http://java.sun.com/xml/ns/persistence/orm}entity-mappings

Source