A Lightning component can execute a complex SOQL query that joins two objects by invoking an Apex class with the method annotated as @AuraEnabled. This annotation enables the Apex method to be called from the Lightning component's JavaScript controller or helper. The Apex method can then perform the SOQL query and return the results to the Lightning component. This approach allows the Lightning component to leverage the programmatic capabilities of Apex and SOQL to perform complex queries that are not possible with declarative tools such as flows or standard components. References:
* Certification - Platform Developer I - Trailhead, Section 5. Exam Outline, Topic: Logic and Process Automation, Weight: 46%, Objective: Describe how to use declarative and programmatic methods to create custom user interfaces on the Lightning Platform.
* [Call Apex Methods from Lightning Web Components], Trailhead Module, Unit: Call Apex Methods Imperatively
* [SOQL and SOSL Queries], Salesforce Developer Guide, Chapter: SOQL and SOSL Reference