IsSchemaValid does chang the xml-encoding header from UTF-8 to WINDOWS-1252

Question

I found the following effect:
isSchemaValid does changing the encoding - entry of the xml-file-header
generating xml-file by using DBMS_XMLGEN :
xmldoc := DBMS_XMLGEN.getXML(ctx);
with the header of the file is
<?xml version="1.0" encoding="UTF-8"?>
change the xmldoc to a xmlType
and validate it against the schema
xmldoc_xmlType:=(xmltype(xmldoc)) ;
xmldoc_xmlType.isSchemaValid ( bSchemalocation)
after this the header of the file is
<?xml version="1.0" encoding="WINDOWS-1252"?>
my DB:
R11_2_0_2 / Windows 64
the same in
R11_2_0_1 / Windows 32
select name, value from v$parameter where upper(name) like '%NLS%'
nls_calendar     
nls_comp          BINARY
nls_currency     
nls_date_format     
nls_date_language     
nls_dual_currency     
nls_iso_currency     
nls_language          AMERICAN
nls_length_semantics     BYTE
nls_nchar_conv_excp     FALSE
nls_numeric_characters     
nls_sort     
nls_territory          AMERICA
nls_time_format     
nls_timestamp_format     
nls_timestamp_tz_format     
nls_time_tz_format     
register my schema by:
dbms_xmlschema.registerSchema(
schemaurl => vschemaurl,
schemadoc => xsd_file,
local      => FALSE,      
gentypes      => TRUE,      
genbean      => FALSE,      
gentables      => TRUE,      
force      => FALSE,
owner      => dbuser
,CSID      => nls_charset_id('AL32UTF8')
How can I let or change back the xml-encoding entry to UTF-8 ?
regards

Answer 1

Your solution should not be relied upon...
C:\Temp>sqlplus /nolog @t1 %CD%
SQL*Plus: Release 11.2.0.2.0 Production on Fri Mar 4 09:41:32 2011
Copyright (c) 1982, 2010, Oracle.  All rights reserved.
SQL> spool testcase.log
SQL> --
SQL> connect sys/oracle as sysdba
Connected.
SQL> --
SQL> set define on
SQL> set timing on
SQL> --
SQL> def XMLDIR = &1
SQL> --
SQL> def USERNAME = XDBTEST
SQL> --
SQL> def PASSWORD = &USERNAME
SQL> --
SQL> def USER_TABLESPACE = USERS
SQL> --
SQL> def TEMP_TABLESPACE = TEMP
SQL> --
SQL> drop user &USERNAME cascade
  2  /
old   1: drop user &USERNAME cascade
new   1: drop user XDBTEST cascade
User dropped.
Elapsed: 00:00:00.24
SQL> grant create any directory, drop any directory, connect, resource, alter session, create view to &USERNAME identified by &PASSWORD
  2  /
old   1: grant create any directory, drop any directory, connect, resource, alter session, create view to &USERNAME identified by &PASSWORD
new   1: grant create any directory, drop any directory, connect, resource, alter session, create view to XDBTEST identified by XDBTEST
Grant succeeded.
Elapsed: 00:00:00.07
SQL> alter user &USERNAME default tablespace &USER_TABLESPACE temporary tablespace &TEMP_TABLESPACE
  2  /
old   1: alter user &USERNAME default tablespace &USER_TABLESPACE temporary tablespace &TEMP_TABLESPACE
new   1: alter user XDBTEST default tablespace USERS temporary tablespace TEMP
User altered.
Elapsed: 00:00:00.00
SQL> set long 100000 pages 0 lines 256 trimspool on timing on
SQL> --
SQL> connect &USERNAME/&PASSWORD
Connected.
SQL> --
SQL> create or replace directory XMLDIR as '&XMLDIR'
  2  /
old   1: create or replace directory XMLDIR as '&XMLDIR'
new   1: create or replace directory XMLDIR as 'C:\Temp'
Directory created.
Elapsed: 00:00:00.00
SQL> create table XML_DEFAULT of XMLTYPE
  2  /
Table created.
Elapsed: 00:00:00.11
SQL> create table XML_CLOB of XMLTYPE
  2  XMLTYPE store as CLOB
  3  /
Table created.
Elapsed: 00:00:00.01
SQL> select *
  2    from nls_database_parameters
  3   where parameter in ('NLS_LANGUAGE', 'NLS_TERRITORY', 'NLS_CHARACTERSET')
  4  /
NLS_LANGUAGE                   AMERICAN
NLS_TERRITORY                  AMERICA
NLS_CHARACTERSET               AL32UTF8
Elapsed: 00:00:00.02
SQL> declare
  2    XML_DEFAULT XMLType := xmltype('<?xml version="1.0" encoding="WINDOWS-1252"?><TEST>SELECT</TEST>') ;
  3    XML_CLOB    XMLType := xmltype('<?xml version="1.0" encoding="WINDOWS-1252"?><TEST>SELECT</TEST>') ;
  4  begin
  5    delete XML_DEFAULT;
  6    delete XML_CLOB;
  7    insert into XML_DEFAULT values (XML_DEFAULT);
  8    dbms_xslprocessor.clob2file( XML_DEFAULT.getclobval() , 'XMLDIR','XML_DEFAULT.xml');
  9    IF  XML_DEFAULT.isSchemaValid ( 'SCHEMALOCATION_DOES_NO_MATTER_FOR_TEST_CASE.XSD', 'SCHEMA_NO_MATTER') = 1 THEN  null; ELSE  null; END IF;
10    commit;
11    dbms_xslprocessor.clob2file( XML_DEFAULT.getclobval() , 'XMLDIR','XML_DEFAULT_IS_VALID.xml',nls_charset_id('WE8MSWIN1252'));
12    dbms_xslprocessor.clob2file( XML_DEFAULT.getclobval() , 'XMLDIR','XML_DEFAULT_WIN1252.xml');
13    insert into XML_CLOB values (XML_CLOB);
14    dbms_xslprocessor.clob2file( XML_CLOB.getclobval() , 'XMLDIR','XML_CLOB.xml');
15    commit;
16  end ;
17  /
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.27
SQL> --
SQL> host type XML_DEFAULT.xml
<?xml version="1.0" encoding="WINDOWS-1252"?><TEST>SELECT</TEST>
SQL> --
SQL> host type XML_DEFAULT_IS_VALID.xml
<?xml version="1.0" encoding="UTF-8"?>
<TEST>SELECT</TEST>
SQL> --
SQL> host type XML_DEFAULT_WIN1252.xml
<?xml version="1.0" encoding="UTF-8"?>
<TEST>SELECT</TEST>
SQL> --
SQL> host type XML_CLOB.xml
<?xml version="1.0" encoding="WINDOWS-1252"?><TEST>SELECT</TEST>
SQL> --
SQL>First, the character set changes because isSchemaValid() causes the document to be parsed and converted to the internal database character set, as does storing it in a table.
It appear that your solution works in SQL because the semantics of SQL are such that it causes a 'copy' of the XMLType to take place before running the isSchemaValid() processing, were we to optimize away that copy as a result of a patch or performance optimization project then you solution would break...
If you want the output in a particular character set you should force that using XMLSerialize or getBlobVal(charsetid). Unfortunately we don't have a convience method for writing BLOBS on DBMS_XSLPROCESSOR...