Access Nested Map With Using Escape Character in Esper

Question

I have a LinkedHashMap like so:

{_index=1, _type=zz, _source={custom_field=custom, field_0=Group, field_10=was, field_3}}

Using an EPL statement, how can I access the custom_field in a EPL statement. Here are some things I've tried

String expression = "select `_source.custom_field` from MyMapEvent";
String expression = "select \\_source.custom\\_field` from MyMapEvent";

The escape characters documentation can be found here: http://esper.codehaus.org/esper-4.6.0/doc/reference/en-US/html_single/index.html#eventrep-properties-escaping

Answer 1

I have tried this and it works: create schema MyInnerEvent(_c int); create schema MyEvent(_a int, _b MyInnerEvent); select _b._c from MyEvent;