Problem with gantt chart displaying - Apex4.2

Question

Hi I'm using Apex 4.2 on localhost and
I have got three tables: employee, engineer, dates
-> engineer table is a specification of employee table, that means in employee you can find also the
names of the engineers. Engineer only has an additional attribute.
Here's the structure of the three tables:
employee (e_id, lastname, surname....)
engineer (e_id, attribute)
appointment (a_id, e_id,start, end)
Now my problem: By using the gantt chart the xml doesn't want to show the names of the engineers.
If I only use this sql statement everything works but I only have the e_id from my engineer table:
select
null link,
a.e_id,
(select e_id from engineer where e_id = a.e_id) Engineer,
null parent_id,
a.start,
a.end
from appointment a
If I try to use this statement in order to see the names of the employees no chart will be shown,
only xml error:
select
null link,
a.e_id,
(select emp.lastname from employee emp, engineer e where emp.e_id = e.e_id and e.e_id=a.e_id) Engineer,
null parent_id,
a.start,
a.end
from appointment a
I also created a view which combines the lastname from employee and the e_id from engineer
but same problem.
If I try:
select
null link,
a.e_id,
(select e_id from gantt_view where e.e_id=a.e_id) Engineer,
null parent_id,
a.start,
a.end
from appointment a
Then I'll see e_ids in my gantt chart but if I want to see my employee names
with this statement:
select
null link,
a.e_id,
(select lastname from gantt_view where e.e_id=a.e_id) Engineer,
null parent_id,
a.start,
a.end
from appointment a
Nothing is shown on the gantt chart.
I tested all sql statements on sql developer.
There I was able to see my employee names.
But for gantt charts it doesn't work.
Any solutions?

Answer 1

Great!
Of course, hard to diagnose when there's nothing to see.
Here's an old message in a thread from 2010. (To give credit, it's from Hilary Farrell.)
>
You are correct, the syntax outlined in the error message is incorrect, and I've logged bug 9799373 to track this. As a workaround, you can view sample syntax for Gantt charts on the 'Query' page of the Create wizard, in the 'Chart Query Example for Gantt' Show/Hide region below the text area for entering your chart query, and also in the Oracle APEX 4.0 User's Guide that will be available with our new release. Just in case other users hit the same issue and are unsure of the expected format:
Chart Query Examples for Project Gantt Charts:
SELECT NULL LINK,
TASK_NAME NAME,
TASK_ID ID,
NULL PARENT_ID,
START_DATE ACTUAL_START,
END_DATE ACTUAL_END,
STATUS_NUMBER PROGRESS
FROM TASKS
SELECT 'f?p=4000:2:'||:APP_SESSION||':::P2_ID:'||ID LINK
TASK_NAME NAME,
TASK_ID ID,
PARENT_TASK_ID PARENT_ID,
START_DATE ACTUAL_START,
END_DATE ACTUAL_END,
STATUS_NUMBER PROGRESS
FROM TASKS
SELECT NULL LINK,
TASK_NAME NAME,
TASK_ID ID,
NULL PARENT_ID,
START_DATE ACTUAL_START,
END_DATE ACTUAL_END,
STATUS_NUMBER PROGRESS,
START_DATE-3 PLANNED_START,
END_DATE+1 PLANNED_END
FROM TASKS
Chart Query Examples for Resource Gantt Charts:
SELECT NULL LINK,
RESOURCE_ID ID,
NULL NAME,
NULL PARENT_ID,
START_DATE ACTUAL_START,
END_DATE ACTUAL_END
FROM TASKS
SELECT 'f?p=4000:2:'||:APP_SESSION||':::P2_ID:'||ID LINK
RESOURCE_ID ID,
RESOURCE_NAME NAME,
PARENT_ID PARENT_ID,
START_DATE ACTUAL_START,
END_DATE ACTUAL_END
FROM TASKS
Thanks for reporting this issue, and I'm happy you were able to successfully generate your chart.
Regards,
Hilary
Can you show us the query you are using?
Oh. And what are the data types and lengths of your data?
Howard