Oracle Database 11g Building Oracle XML DB Applications

DTD Validation

DTD defines the XML structure with a list of elements, attributes, and entities. DTD is widely used in document-centric applications. DTD can be stored as a file or embedded in XML documents. The DTDs included within an XML document are called “internal DTDs.” An example is shown as follows (contact_list_in.xml):

<?xml version = ‘1.0’ encoding = ‘UTF-8’?>

<!DOCTYPE contact_list[

<!ELEMENT contact_list (contact+)>

<!ELEMENT contact (first_name,last_name)>

<!ELEMENT first_name (#PCDATA)>

<!ELEMENT last_name (#PCDATA)>

<!ATTLIST contact id CDATA #REQUIRED>

<!ENTITY author “John Smith”>

<!ENTITY book “Oracle Database 11g: Building Oracle XML DB Applications”>]>

<contact_list>

<contact id=“1”>

     <first_name>John</first_name>

     <last_name>Smith</last_name> ...