17.10 - XMLEXTRACT Syntax - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - XML Data Type

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1140-171K
Language
English (United States)
XMLEXTRACT (
  [ filterExpr, ]
  query,
  nsmap
)

Syntax Elements

filterExpr
An optional filter expression that allows for streamed evaluation of the query expression.
filterExpr is required if the query is being evaluated over a large XML value.
filterExpr must be VARCHAR(n), where the maximum supported size (n) is 512.
query
The XPath or XQuery query string.
query must be VARCHAR(n), where the maximum supported size (n) is 8192.
nsmap
Namespace declarations.
nsmap must be VARCHAR(n), where the maximum supported size (n) is 1024.
You can declare namespaces in two ways:
  • Declare the namespaces in the query string. For example:
    SELECT CREATEXML('<a xmlns="http://td.com"><b>c</b><b>d</b></a>').XMLEXTRACT('declare namespace td = "http://td.com"; /td:a/td:b', NULL);

    The namespace is declared at the beginning of the query: declare namespace td = "http://td.com"

  • Specify the namespaces in the nsmap parameter as a string of prefix=namespace_uri declarations with a space separating each namespace declaration. For example:
    SELECT CREATEXML('<a xmlns="http://td.com"><b>c</b><b>d</b></a>').XMLEXTRACT('/td:a/td:b', 'td=http://td.com');