<value> IS NOT NULLNOTEThe operators
==and!=cannot be used to evaluate null values.
Sample graph: (to be used for the following examples)

UQLcreate().node_property(@default, "name").node_property(@default, "try1", int32).node_property(@default, "try2", int32).node_property(@default, "try3", int32) insert().into(@default).nodes([{name:"Jason", try1:84}, {name:"Alice", try1:55, try2:79}, {name:"Lina"}, {name:"Eric", try1:39, try2:46, try3:61}, {name:"Pepe", try1:89}])
Example: Return the name of student who took the 2nd test (the 1st re-test)
UQLfind().nodes({try2 is not null }) as n return n.name
ResultAlice Eric