-- https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/Using-XML-in-SQL-Statements.html
SELECT * FROM xwarehouses x 
   WHERE EXISTSNODE(VALUE(x), '/Warehouse[WarehouseId="1"]',
   'xmlns:who="http://www.example.com/xwarehouses.xsd"') = 1;
SELECT * FROM xwarehouses x
   WHERE EXTRACTVALUE(VALUE(x), '/Warehouse/WarehouseId',
   'xmlns:who="http://www.example.com/xwarehouses.xsd"') = 1;