Chart Labels In Apex

Question

So I'm trying to create a chart that groups an aggregate function by the primary key. On the label, I cannot figure out how to query a lable that shows the primary key and the name of the customer that is located in a different table. I'm learning how to develop in Apex so I'm using the sample database right now. The following query adds up the order total by customer but I want the label to not just say the primary key (customer_ID) but also the customer last name (Cust_last_name) located in the demo_customers table. Here is the query:
select null link, CUSTOMER_ID label, SUM(ORDER_TOTAL) value1
from "LEARNING"."DEMO_ORDERS"
group by CUSTOMER_ID
Also I built this query with the query builder. Can someone explain the purpose of the "Null Link" in the select clause? And how can I get the percentages to show in a pie chart?
Edited by: 1001737 on Apr 22, 2013 2:23 PM

Answer 1

Hi, welcome to the forum. Please access your Control Panel and update your handle to something a bit more personal than 1001737.
When you said:
I want the label to not just say the primary key (customer_ID) but also the customer last name (Cust_last_name) located in the demo_customers table You were half way there, you just need to join your current query to the demo_customers table to retrieve the customers last name and use that as the label on your chart.
Try this version of the query in your chart series; I find that a pie chart is best for this purpose:
select
   null link,
   cust_last_name label,
   round(sum(order_total/total.tot),
   2) value  -- determine percentage of all orders 
from
   demo_orders,
   demo_customers,
   (select
      sum(order_total)tot
   from
      demo_orders) total -- sum all orders 
where
   demo_orders.customer_id = demo_customers.customer_id 
group by
   cust_last_nameYou asked
Can someone explain the purpose of the "Null Link" in the select clause?Placing NULL here states that you are choosing not to allow the action of a link when one of the chart labels is clicked. See this site for some excellent charting examples and further explanation:
[url [http://apex.oracle.com/pls/apex/f?p=36648]Sample Charts, Maps, Gantts and Trees
And how can I get the percentages to show in a pie chart?Percentages need to be calculated; to add the *%* to the label, set the Postfix within the Display Settings of Chart Attributes.
Jeff