You can use Oracle XML DB XMLType PL/SQL, Java, C APIs, and Oracle Data Provider for .NET (ODP.NET) to access and manipulate XML data.

• PL/SQL APIs for XMLType
  There are several PL/SQL packages that provide APIs for XMLType.
• PL/SQL Package DBMS_XMLSTORE
  You can use PL/SQL package DBMS_XMLSTORE to insert, update, or delete data from XML documents stored object-relationally. It uses a canonical XML mapping similar to the one produced by package DBMS_XMLGEN. It converts the mapping to object-relational constructs and then inserts, updates or deletes the corresponding values in relational tables.
• Java DOM API for XMLType
  The Java DOM API for XMLType lets you operate on XMLType instances using a DOM. You can use it to manipulate XML data in Java, including fetching it through Java Database Connectivity (JDBC).
• C DOM API for XMLType
  The C DOM API for XMLType lets you operate on XMLType instances using a DOM in C.
• Oracle XML DB and Oracle Data Provider for .NET
  Oracle Data Provider for Microsoft .NET (ODP.NET) is an implementation of a data provider for Oracle Database. It uses Oracle native APIs to offer fast and reliable access to Oracle data and features from any .NET application.