我正在使用 PostgreSQL 9.1,我认为它应该支持这种 XML 集成,但我无法让它工作。我试试这个查询:
select data from ddm_table_data order by pgxml_xpath(data, '//xmltest/col1/text()', '', '');
它出现了以下错误:
ERROR: function pgxml_xpath(xml, unknown, unknown, unknown) does not exist
SQL state: 42883
Hint: No function matches the given name and argument types. You might need to add explicit type casts.
我错过了什么吗?