Scalar. Determines whether or not the results of an XPATH expression exists in an XML element.
Sybase CEP evaluates xpath and returns True if it locates the results in value, False if it does not, and Null if evaluating xpath results in Null or an error.
XMLEXTRACT
The following example shows testing for PA as the state:
INSERT INTO OutStream
SELECT orderid, customername
FROM Order2
WHERE XMLEXISTS ('//state[.=''PA'']', PASSING orderval2);