Exporting DB data to XML based on a pre-defined XSD

Question

Hi,
I am new to PL/SQL and would need some good examples of code how to export database extries into an XML file based on a predefined XSD.
Input:
TABLE1
fields: ID (PK), NAME, X, Y, BLOB
TABLE2
fields: ID (FK), DESCRIPTION
Both tables have a relationships. Inside the BLOB is a saved XML file that also needs to get exported. I would need a sample of SQL or PL/SQL code how to export a BLOB into an XML.
Thanks!

Answer 1

Hi,
You can use dbms_metada built-in package in order to generate database structure(metadata) in an XML file. This package is very complex and flexible. You can get more examples on tahiti.oracle.com or psoug.org as damorgan mentioned.
As i read from your question, you need to export-extract table rows-entities in a file, simply. You also need a predefined XSD. Once i need to export table data programatically. You can find more utilities by googling. If you wish, you can reach my package here . However it is not completely covers your req. but i also post simple output in order to understand whether it is helpful or not for your requirements.
Reg.
PROCEDURE ExportFile
--oracle directory name
pis_DirectoryName in VARCHAR2,
--file name
pis_FileName in VARCHAR2,
--table name that will be exported
pis_TableName IN ALL_TABLES.TABLE_NAME%TYPE,
--filter criteria,if exists
pis_WhereCondition IN VARCHAR2 DEFAULT NULL,
--if table has more columns how fields will be seperated
pis_FieldDelimiter IN VARCHAR2 DEFAULT ',',
--row delimiter, CHR(10) for newline
pis_RecordDelimiter IN VARCHAR2 DEFAULT CHR(10),
--if some columns will not be included
pis_ExceptedFieldList IN VARCHAR2 DEFAULT NULL,
--1 for fields enclosed by ", such as "column_value"
pin_FieldEnclosedByQuote IN NUMBER DEFAULT 0,
--if column name will not be included, set as 0
pin_IncludeColumnName IN NUMBER DEFAULT 0,
--if field names included
pis_FieldNameDelimiter IN VARCHAR2 DEFAULT ':'
SQL> create table t
  2  (
  3  i number,
  4  xml_data blob
  5  );
Table created.
SQL>
SQL> insert into t values (1, rawtohex('
  2  <books>
  3     <book>
  4        <author>bla bla bla</author>
  5        <title>falan filan</title>
  6     </book>
  7  </books>') );
1 row created.
SQL>
SQL> create or replace directory TEST_DIR as 'c:\test';
Directory created.
SQL> BEGIN
  2    UTL_EXP.ExportFile(pis_DirectoryName  => 'TEST_DIR',
  3                       pis_FileName       => 'test.xml',
  4                       pis_TableName      => 't',
  5                       pis_WhereCondition => 'i = 1');
  6  END;
  7  /
PL/SQL procedure successfully completed.
SQL>
SQL> exit
Disconnected from Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
C:\Users\Mennan>type c:\test\test.xml
1,
<books>
   <book>
      <author>bla bla bla</author>
      <title>falan filan</title>
   </book>
</books>,
C:\Users\Mennan>