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Using schemas with XML DB

dbms_xmlschema can be used to register schemas with XML DB.

Annotating Schemas for XML DB

Schemas can/must be annotated for the use in XML DB. These annotations control how XML documents are stored in the database. The attributes for the annotations are in a different namespace than the Schema attributes.
The most used annotations are
  • defaultTable
  • SQLName
  • SQLType
  • SQLCollType
  • maintainDOM
  • storeVarraysAsTable

Local and global Schemas

A Schema can either be registered globally or locally. If it is registered locally, it is only visible to the user who registered it, otherwise, it is visible to all database users.

An example

begin
  dbms_xmlschema.registerSchema (
  'some_dummy_url',
  '
  <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  
    <xsd:complexType name="T_person">
  
      <xsd:all>
        <xsd:element name="first_name"  type="xsd:string"          />
        <xsd:element name="last_name"   type="xsd:string"          />
        <xsd:element name="birth_day"   type="xsd:date"            />
      </xsd:all>
  
      <xsd:attribute name="employee_id" type="xsd:positiveInteger" />
  
    </xsd:complexType>
  
    <xsd:element name="person" type="T_person" />
  
  </xsd:schema>
  ',
  true,   -- local
  true,   -- schema compiler will generate object types
  false,  -- don't generate java beans
  false   -- don't allow invalid schemas
);
end;
/

create table xml_person of xmltype 
xmlschema "some_dummy_url"   -- Note: these are double quotes, not single quotes!
element "person";

insert into xml_person values (
  xmltype ('
    <person employee_id="3094"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    >
      <birth_day>1968-05-31</birth_day>
      <first_name>Mark</first_name>
      <last_name>Denver</last_name>
    </person>
','some_dummy_url')
);