A GROUP BY question

[stan <stanb@xxxxxxxxx>]

I am trying to write, what is for me, a fairly complex query. It uses JOINS,
and also GROUP BY. I have this working with the exception of adding the
GROUP BY clause. 

Is there some reason I cannot add a GROUP BY function to a JOIN?

Here is what I have:


CREATE OR REPLACE view tasks_view as 
select 
	project.proj_no ,
	employee.first_name ,
	employee.last_name ,
	employee.id ,
	task_instance.hours , 
	work_type.type,
	work_type.descrip,
	rate.rate,
	employee.hourly_rate ,
	rate.rate * task_instance.hours as result ,
	SUM(rate.rate * task_instance.hours) 
	^^^^^^^^^^^^^^
from 
	task_instance
GROUP BY 
^^^^^^^^^^^^^^^^^^
	project.project_key 
^^^^^^^^^^^^^^^^^^^^^^
join rate on 
	rate.employee_key = task_instance.employee_key
	AND
	rate.work_type_key = task_instance.work_type_key
inner join employee on
	rate.employee_key = employee.employee_key
inner join work_type on
	rate.work_type_key = work_type.work_type_key
inner join project on
	project.project_key = task_instance.project_key
ORDER BY 
	project.proj_no ,
	employee.id
	;

The underlined lines are what I added, and I get a syntax error pointing to
the join. This works fine without the added lines.

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