1. A computer-implemented method for complex event handling, comprising: providing, within a complex event handling system, a rule implementation system comprising an interface to a graph database for storing rules and facts; providing, separately from the rule implementation system, an event log comprising a history of past events and associated prior event parameters for future rule testing; receiving, by the rule implementation system, a rule comprising a rule condition and a rule result such that when the rule condition obtains, the rule is triggered causing the rule result to be executed; analyzing, by the rule implementation system, the rule condition to extract two or more condition entities and one or more condition relationships; converting, by the rule implementation system, the received rule condition to a condition graph comprising two or more nodes representing the two or more condition entities, and one or more edges representing the condition relationships; analyzing, by the rule implementation system, the rule result to extract one or more result entities and one or more result actions; converting, by the rule implementation system, the rule result into a result graph comprising one or more nodes representing the one or more result entities; inserting, by the rule implementation system, edges representing the result actions to connect the condition graph and the result graph to form a rule graph; storing, by the rule implementation system, the rule graph into the graph database; receiving, by the complex event handling system, a current event; identifying, by the complex event handling system, one or more rule graphs, within the rule implementation system, wherein the respective identified condition graph associated with each of the one or more rule graphs comprises condition entities associated with both the current event and a past occurrence of a particular prior event; searching, by the complex event handling system, the event log for the particular prior event; retrieving, by the complex event handling system, prior event parameters, from the event log, corresponding to the particular prior event; performing, by the rule implementation system, a query against the graph database to evaluate the identified condition graph in response to both the current event and the retrieved prior event parameters; and executing, by the rule implementation system, the associated result actions upon the result graph associated with the identified condition graph in response to the performed query.