ORA-30938: No prefix defined for namespace 'string' (particle string)
Cause: An XML namespace mapping (xmlns:=) must be defined for each particle (element or attribute) stored in an schema-constrained XMLType document
Action: Add an xmlns attribute definition (attribute name="xmlns:prefix" and value="namespace URL") to the current XMLType document. The safest place to add this attribute is in the root node of the document to ensure that the mapping will be in scope
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