Problem in XSD and XSLT

Question

Actually I have a problem relating to Oracle 10g XML DB. I’ll explain the scenario.
1.     First an xml file needs to be loaded into the database( after registering the schema)
2.     Later maybe after inserting suppose 10 xml files into the table, I need to add an element in the xml.
3. And the new xml's which are later loaded will have that additional field coming in. so how should I go about from here.
What I’ve thought is:
1.     Generate a new XSD schema (don’t know how to generate this automatically), implementing the additional field change.(can u help me in this)
2.     Create a new XSL depending on the new XSD schema (don’t know how to generate this automatically). (can u help me in this)
3.     apply the new xsl to the original xml to get the new xml.
4.     in the meantime, keep the old xml in a temporary tables, and later, update those xml corresponding to the new schema (can u help me in this)
I don’t know if this a correct procedure, if in case, there is a different and an easy method to do it, please let me know.
regards,
athar

Answer 1

Does the following help
SQL> set long 10000 pages 50
SQL> --
SQL> declare
  2    res boolean;
  3    xmlschema xmltype := xmltype(
  4  '<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xdb="http://x
  5     <xsd:complexType name="T_person" xdb:SQLType="PERSON_T">
  6       <xsd:all>
  7         <xsd:element name="first_name" type="xsd:string" />
  8         <xsd:element name="last_name" type="xsd:string" />
  9         <xsd:element name="birth_day" type="xsd:date" />
10       </xsd:all>
11       <xsd:attribute name="employee_id" type="xsd:positiveInteger" />
12     </xsd:complexType>
13     <xsd:element name="person" type="T_person" xdb:defaultTable="XML_LOAD"/>
14  </xsd:schema>');
15  begin
16    if (dbms_xdb.existsResource('/public/testcase.xsd')) then
17      dbms_xdb.deleteResource('/public/testcase.xsd');
18    end if;
19    res := dbms_xdb.createResource('/public/testcase.xsd',xmlschema);
20  end;
21  /
PL/SQL procedure successfully completed.
SQL> call dbms_xmlschema.deleteSchema('www.WMDurl.com',4)
  2  /
Call completed.
SQL> begin
  2    dbms_xmlschema.registerSchema ('www.WMDurl.com',xdburitype('/public/testcas
  3  end;
  4  /
PL/SQL procedure successfully completed.
SQL> desc XML_LOAD
Name                                      Null?    Type
TABLE of SYS.XMLTYPE(XMLSchema "www.WMDurl.com" Element "person") STORAGE Object-r
SQL> --
SQL> desc PERSON_T
PERSON_T is NOT FINAL
Name                                      Null?    Type
SYS_XDBPD$                                         XDB.XDB$RAW_LIST_T
employee_id                                        NUMBER(38)
first_name                                         VARCHAR2(4000 CHAR)
last_name                                          VARCHAR2(4000 CHAR)
birth_day                                          DATE
SQL> --
SQL> insert into xml_load values (xmltype(
  2  '<person employee_id="1">
  3     <first_name>mark</first_name>
  4     <last_name>drake</last_name>
  5     <birth_day>2006-01-31</birth_day>
  6   </person>'
  7  ))
  8  /
1 row created.
SQL> commit
  2  /
Commit complete.
SQL> set long 10000
SQL> --
SQL> select * from xml_load
  2  /
SYS_NC_ROWINFO$
<person employee_id="1">
  <first_name>mark</first_name>
  <last_name>drake</last_name>
  <birth_day>2006-01-31</birth_day>
</person>
SQL> insert into xml_load values (xmltype(
  2  '<person employee_id="1">
  3     <first_name>barney</first_name>
  4     <last_name>rubble</last_name>
  5     <birth_day>2006-01-31</birth_day>
  6     <address>Bedrock</address>
  7   </person>'
  8  ))
  9  /
insert into xml_load values (xmltype(
ERROR at line 1:
ORA-30937: No schema definition for 'address' (namespace '##local') in parent
'/person'
SQL> commit
  2  /
Commit complete.
SQL> set long 10000
SQL> --
SQL> select * from xml_load
  2  /
SYS_NC_ROWINFO$
<person employee_id="1">
  <first_name>mark</first_name>
  <last_name>drake</last_name>
  <birth_day>2006-01-31</birth_day>
</person>
SQL> select xdbUriType('/public/testcase.xsd').getXML()
  2    from dual
  3  /
XDBURITYPE('/PUBLIC/TESTCASE.XSD').GETXML()
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xdb="http://xmlns
.oracle.com/xdb">
  <xsd:complexType name="T_person" xdb:SQLType="PERSON_T">
    <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" xdb:defaultTable="XML_LOAD"/>
</xsd:schema>
SQL> declare
  2    xmlschema xmltype := xdburitype('/public/testcase.xsd').getXML();
  3    res boolean;
  4  begin
  5    select insertChildXML
  6           (
  7             xmlschema,
  8             '/xsd:schema/xsd:complexType[@name="T_person"]/xsd:all',
  9             'xsd:element',
10             xmltype('<xsd:element xmlns:xsd="http://www.w3.org/2001/XMLSchema"
11             'xmlns:xsd="http://www.w3.org/2001/XMLSchema"'
12           )
13      into xmlSchema
14      from dual;
15    if (dbms_xdb.existsResource('/public/newTestcase.xsd')) then
16      dbms_xdb.deleteResource('/public/newTestcase.xsd');
17    end if;
18    res := dbms_xdb.createResource('/public/newTestcase.xsd',xmlschema);
19  end;
20  /
PL/SQL procedure successfully completed.
SQL> select xdbUriType('/public/newTestcase.xsd').getXML()
  2    from dual
  3  /
XDBURITYPE('/PUBLIC/NEWTESTCASE.XSD').GETXML()
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xdb="http://xmlns
.oracle.com/xdb">
  <xsd:complexType name="T_person" xdb:SQLType="PERSON_T">
    <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:element xmlns:xsd="http://www.w3.org/2001/XMLSchema" name="address" t
ype="xsd:string"/>
    </xsd:all>
    <xsd:attribute name="employee_id" type="xsd:positiveInteger"/>
  </xsd:complexType>
  <xsd:element name="person" type="T_person" xdb:defaultTable="XML_LOAD"/>
</xsd:schema>
SQL> begin
  2    dbms_xmlschema.CopyEvolve
  3    (
  4       xdb$string_list_t('www.WMDurl.com'),
  5       XMLSequenceType(xdburitype('/public/newTestcase.xsd').getXML()),
  6       null
  7    );
  8  end;
  9  /
PL/SQL procedure successfully completed.
SQL> desc XML_LOAD
Name                                      Null?    Type
TABLE of SYS.XMLTYPE(XMLSchema "www.WMDurl.com" Element "person") STORAGE Object-r
SQL> --
SQL> desc PERSON_T
PERSON_T is NOT FINAL
Name                                      Null?    Type
SYS_XDBPD$                                         XDB.XDB$RAW_LIST_T
employee_id                                        NUMBER(38)
first_name                                         VARCHAR2(4000 CHAR)
last_name                                          VARCHAR2(4000 CHAR)
birth_day                                          DATE
address                                            VARCHAR2(4000 CHAR)
SQL> --
SQL> insert into xml_load values (xmltype(
  2  '<person employee_id="2">
  3     <first_name>barney</first_name>
  4     <last_name>rubble</last_name>
  5     <birth_day>2006-01-31</birth_day>
  6     <address>Bedrock</address>
  7   </person>'
  8  ))
  9  /
1 row created.
SQL> commit
  2  /
Commit complete.
SQL> set long 10000
SQL> --
SQL> select * from xml_load
  2  /
SYS_NC_ROWINFO$
<person employee_id="1">
  <first_name>mark</first_name>
  <last_name>drake</last_name>
  <birth_day>2006-01-31</birth_day>
</person>
<person employee_id="2">
  <first_name>barney</first_name>
  <last_name>rubble</last_name>
  <birth_day>2006-01-31</birth_day>
  <address>Bedrock</address>
</person>
SQL> update XML_LOAD
  2     set object_value = insertChildXML
  3                        (
  4                          object_value,
  5                          '/person',
  6                          'address',
  7                          xmltype('<address/>')
  8                        )
  9   where existsNode(object_value,'/person/address') = 0
10  /
1 row updated.
SQL> commit
  2  /
Commit complete.
SQL> select * from xml_load
  2  /
SYS_NC_ROWINFO$
<person employee_id="1">
  <first_name>mark</first_name>
  <last_name>drake</last_name>
  <birth_day>2006-01-31</birth_day>
  <address/>
</person>
<person employee_id="2">
  <first_name>barney</first_name>
  <last_name>rubble</last_name>
  <birth_day>2006-01-31</birth_day>
  <address>Bedrock</address>
</person>