How get task from business key

[aram]

Hi.
I am using grails activity plugin. and I like to get all tasks for current document.
to do that I define domain classes "Task" and "Execution" in grains and use following HQL

getTaskForDocument = from Task 
where id in( 
select id from Task where EXECUTION_ID_ in( 
select exec1.id from Execution exec1 where 
exec1.BUSINESS_KEY_=:BUSINESS_KEY and 
exec1.id in( select max(id) from Execution as exec2 where exec2.BUSINESS_KEY_ = exec1.BUSINESS_KEY_ )))
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List tasksForDocument = Task.findAll(getTaskForDocument, [BUSINESS_KEY: "BUSINESS_KEY_here"]);

‍‍‍‍

Is there any other effective way to get Task using BUSINESS_KEY (I don't like to have/define  "Task" and "Execution" domain classes in my app)?

[ronald_van_kuij]

Is there any other effective way to get Task using BUSINESS_KEY (I don't like to have/define "Task" and "Execution" domain classes in my app)?

Define effective… I just use the Activiti api and it performs well…

[aram]

using API I implement

public List<Task> getTasksFromDocumentID(String documentId) {
        List<Execution> executions = ActivitiUtils.getRuntimeService().createExecutionQuery()
                .variableValueEquals('businessKey', documentId)
                .orderByProcessInstanceId().desc().list();
       
        if (executions.size() > 0) {
            return ActivitiUtils.getTaskService().createTaskQuery()
                    .processInstanceId(executions.get(0)?.getProcessInstanceId())
                    .list();
        } else {
            return new ArrayList<Task>();
        }

    }
but here I have 2 querys. Is it possible to have only one query ?