Pass Prompt values into Legend / '-ALL-' filter filters out all records

Question

Hi
I have 2 questions for the same chart so I hope it's OK to add them in one post.
Firstly I have created a chart & added three Select List filters which work fine, the query is below, problem is that when I change back to '-ALL-' I get no data, it has filtered out all records as no data matches the value of '-ALL-' does anyone know the code to get around this?
My chart query;
select null link, P_MONTH AS MONTH, SUM(CALLS) AS data
from DATA.MAIN_DATA
WHERE WAREHOUSE = :P1_WAREHOUSE
AND ANS_UNANS = :P1_ANS_UNANS
AND PRODUCT = :P1_PRODUCT
GROUP BY P_MONTH
As I will have several queries like the one above for different options on the same chart, I would like the Legend to show what the user has chosen each time the options are changed ie;
Something like the bolded text in the query to display the chosen values in the legend;
select null link, P_MONTH AS MONTH, SUM(CALLS) AS 'P1_WAREHOUSE' || 'P1_ANS_UNANS' || 'P1_PRODUCT'
from DATA.MAIN_DATA
WHERE WAREHOUSE = :P1_WAREHOUSE
AND ANS_UNANS = :P1_ANS_UNANS
AND PRODUCT = :P1_PRODUCT
GROUP BY P_MONTH
Any ideas/suggests?

Answer 1

Thanks Andy
I'm having some problems with applying this so it may be best if I show you how I've applied this code.
Here's an example of my data on a made up 'EMP' table;
ENAME     SAL     DEPTNO     DEPARTMENT
SMITH1     1871     345     DEPT1
SMITH2     1953     345     DEPT2
SMITH3     2239     345     DEPT3
SMITH4     492     345     DEPT4
SMITH5     2431     345     DEPT5
SMITH6     2331     345     DEPT6
SMITH7     1003     369     DEPT7
SMITH8     1688     370     DEPT8
SMITH9     2284     371     DEPT9
So I'm only using one table - 'EMP'
I've created 2 LOVs, 'DEPTNO' & 'DNAME'.
'DEPTNO' LOV has the values for the 'DEPTNO' field in the table.
'DNAME' LOV has the values for the 'DEPARTMENT' field in the table.
I then created a chart with the below SQL query as its source;
SELECT NULL LINK,ENAME LABEL,SAL VALUE
FROM EMP
WHERE (DEPTNO = :P1_DEPTNO OR :P1_DEPTNO = 0)
ORDER BY ENAME
The 'Chart Title' field under the 'Chart Attributes' tab has the below added;
Department - &P1_DNAME.
The COMPUTATION is as below;
SLECT NVL(DEPARTMENT, '-ALL-')
FROM EMP
WHERE DEPTNO = :P1_DEPTNO
Could you advise where I may be going wrong as I have the following errors;
1. The chart is working OK with the added '(DEPTNO = :P1_DEPTNO OR :P1_DEPTNO = 0)' clause - but I still get no results for '-ALL-'
2. I can't get the chart to display the current value in the legend - where exactly should I put this line - 'Department - &P1_DNAME.'
3. The Computation is stopping any data from showing in the chart