XMLElement/XMLForest used together with schema

Question

If I want to use schema when generating XML, looks like I have to put all the elements in global scope of the target namespace in the XML schema, otherwise XMLelement/XMLForest will complain that the defintion of the element can not be found.
For example, in the schema, if I use:
<xs:element name="Link">
     <xs:complexType>
     <xs:sequence>
     <xs:element name="NavStateID" type="xs:integer" minOccurs="0"/>
     </xs:sequence>
     </xs:complexType>      
</xs:element>
and Select XMLElement("Link", XMLForest(nav_id AS "NavStateID")) from table
it will complain that NavStateID is not defined in the target namespace of the schema.
I have to use following to get around of this issue:
<xs:element name="Link">
     <xs:complexType>
     <xs:sequence>
     <xs:element ref="NavStateID" minOccurs="0"/>
     </xs:sequence>
     </xs:complexType>      
</xs:element>
<xs:element name="NavStateID" type="xs:integer"/>
Is there other way to get aroud since if the schema is big, there will be name conflict issues if I put all the element defintions in the global scope.

Answer 1

Oops - my bad
Had the namespace for the Schema Instance incorrect in the above example. However I do the cause of the problem. It's the setting of the elementDefaultForm qualified attribute. With it ommitted it defaults to unqualified and you get the error you are reporting..
SQL> DECLARE
  2    xmlSchema xmlType := xmlType(
  3
  4     '<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.abc.com/goodmorning" xmlns="http://www.abc.com/g
oodmorning" xmlns:xdb="http://xmlns.oracle.com/xdb">
  5             <xs:element name="FeatureLinks" xdb:defaultTable="ST_LINK_FEATURE">
  6                     <xs:complexType>
  7                             <xs:sequence>
  8                                     <xs:element name="Link" type="LinkType" maxOccurs="unbounded"/>
  9                             </xs:sequence>
10                     </xs:complexType>
11             </xs:element>
12             <xs:complexType name="LinkType">
13                     <xs:sequence>
14                             <xs:element name="ID" type="xs:integer" minOccurs="0"/>
15                             <xs:element name="Nav_State_ID" type="xs:integer"/>
16                     </xs:sequence>
17             </xs:complexType>
18     </xs:schema>');
19
20     res boolean;
21     xmlData XMLTYPE;
22     schemaURL VARCHAR2(256):='http://localhost:8080/RDF/st_link_feature.xsd';
23     schemaPath VARCHAR2(256):='/public/st_link_feature.xsd';
24     xmlPath VARCHAR2(256):='/public/test.xml';
25
26  BEGIN
27     IF (dbms_xdb.existsResource(schemaPath)) THEN
28             dbms_xmlSchema.deleteSchema(schemaURL,4);
29             dbms_xdb.deleteResource(schemaPath);
30     END IF;
31     res := dbms_xdb.createResource(schemaPath,xmlSchema);
32     dbms_xmlschema.registerSchema(schemaURL,xdbURIType(schemaPath).getClob(),TRUE,TRUE,FALSE,TRUE);
33  END;
34
35  /
PL/SQL procedure successfully completed.
SQL> drop table ST_LINK_DATA
  2  /
Table dropped.
SQL> create table ST_LINK_DATA
  2  (
  3     ID     varchar2(20),
  4     NAV_ID varchar2(20)
  5  )
  6  /
Table created.
SQL> insert into ST_LINK_DATA values ('456','123')
  2  /
1 row created.
SQL> commit
  2  /
Commit complete.
SQL> set long 100000
SQL> --
SQL> select xmlelement
  2         (
  3            "FeatureLinks",
  4            xmlAttributes
  5            (
  6               'http://www.w3.org/2001/XMLSchema-instance' as "xmlns:xsi",
  7               'http://www.abc.com/goodmorning' as "xmlns",
  8               'http://www.abc.com/goodmorning http://localhost:8080/RDF/st_link_feature.xsd' as "xsi:schemaLocation"
  9            ),
10            xmlElement
11            (
12               "Link",
13               xmlForest
14               (
15                  NAV_ID as "Nav_State_ID"
16               )
17            )
18        ).extract('/*')
19   from ST_LINK_DATA
20  /
ERROR:
ORA-30937: No schema definition for 'Link' (namespace
'http://www.abc.com/goodmorning') in parent '/FeatureLinks'
ORA-06512: at "SYS.XMLTYPE", line 111
no rows selected
SQL> declare
  2   myxml xmltype;
  3  begin
  4    select xmlelement
  5         (
  6            "FeatureLinks",
  7            xmlAttributes
  8            (
  9               'http://www.w3.org/2001/XMLSchema-instance' as "xmlns:xsi",
10               'http://www.abc.com/goodmorning' as "xmlns",
11               'http://www.abc.com/goodmorning http://localhost:8080/RDF/st_link_feature.xsd' as "xsi:schemaLocation"
12            ),
13            xmlElement
14            (
15               "Link",
16               xmlForest
17               (
18                  NAV_ID as "Nav_State_ID"
19               )
20            )
21        ).extract('/*')
22    into myXML
23    from ST_LINK_DATA;
24    myXML := myXML.createSchemaBasedXML();
25    myXML.schemaValidate();
26  end;
27  /
declare
ERROR at line 1:
ORA-30937: No schema definition for 'Link' (namespace
'http://www.abc.com/goodmorning') in parent '/FeatureLinks'
ORA-06512: at "SYS.XMLTYPE", line 111
ORA-06512: at line 4
SQL>With it present and set to qualified everthing works as expected
SQL> DECLARE
  2    xmlSchema xmlType := xmlType(
  3
  4     '<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.abc.com/goodmorning" xmlns="http://www.abc.com/g
oodmorning" xmlns:xdb="http://xmlns.oracle.com/xdb" elementFormDefault="qualified">
  5             <xs:element name="FeatureLinks" xdb:defaultTable="ST_LINK_FEATURE">
  6                     <xs:complexType>
  7                             <xs:sequence>
  8                                     <xs:element name="Link" type="LinkType" maxOccurs="unbounded"/>
  9                             </xs:sequence>
10                     </xs:complexType>
11             </xs:element>
12             <xs:complexType name="LinkType">
13                     <xs:sequence>
14                             <xs:element name="ID" type="xs:integer" minOccurs="0"/>
15                             <xs:element name="Nav_State_ID" type="xs:integer"/>
16                     </xs:sequence>
17             </xs:complexType>
18     </xs:schema>');
19
20     res boolean;
21     xmlData XMLTYPE;
22     schemaURL VARCHAR2(256):='http://localhost:8080/RDF/st_link_feature.xsd';
23     schemaPath VARCHAR2(256):='/public/st_link_feature.xsd';
24     xmlPath VARCHAR2(256):='/public/test.xml';
25
26  BEGIN
27     IF (dbms_xdb.existsResource(schemaPath)) THEN
28             dbms_xmlSchema.deleteSchema(schemaURL,4);
29             dbms_xdb.deleteResource(schemaPath);
30     END IF;
31     res := dbms_xdb.createResource(schemaPath,xmlSchema);
32     dbms_xmlschema.registerSchema(schemaURL,xdbURIType(schemaPath).getClob(),TRUE,TRUE,FALSE,TRUE);
33  END;
34
35  /
PL/SQL procedure successfully completed.
SQL> drop table ST_LINK_DATA
  2  /
Table dropped.
SQL> create table ST_LINK_DATA
  2  (
  3     ID     varchar2(20),
  4     NAV_ID varchar2(20)
  5  )
  6  /
Table created.
SQL> insert into ST_LINK_DATA values ('456','123')
  2  /
1 row created.
SQL> commit
  2  /
Commit complete.
SQL> set long 100000
SQL> --
SQL> select xmlelement
  2         (
  3            "FeatureLinks",
  4            xmlAttributes
  5            (
  6               'http://www.w3.org/2001/XMLSchema-instance' as "xmlns:xsi",
  7               'http://www.abc.com/goodmorning' as "xmlns",
  8               'http://www.abc.com/goodmorning http://localhost:8080/RDF/st_link_feature.xsd' as "xsi:schemaLocation"
  9            ),
10            xmlElement
11            (
12               "Link",
13               xmlForest
14               (
15                  NAV_ID as "Nav_State_ID"
16               )
17            )
18        ).extract('/*')
19   from ST_LINK_DATA
20  /
XMLELEMENT("FEATURELINKS",XMLATTRIBUTES('HTTP://WWW.W3.ORG/2001/XMLSCHEMA-INSTAN
<FeatureLinks xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http:
//www.abc.com/goodmorning" xsi:schemaLocation="http://www.abc.com/goodmorning ht
tp://localhost:8080/RDF/st_link_feature.xsd">
  <Link>
    <Nav_State_ID>123</Nav_State_ID>
  </Link>
</FeatureLinks>
SQL>