Hiding List based on variable via Conditional block - Report Studi

[Luhaine]

Hello everyone,

I have two request I'd like to make of this community.

1. Could you look at my problem, as described below, and provide me with any hints and tips to a possible solution?
2. I have had trouble finding any user driven forum for Cognos Report studio besides this one. Could someone point out some more, if there are any.

Background Info:

I’m relatively new to Cognos Report studio and I'm currently trying to finalize a report about mobile phone use. However I have run into a little snag. I'm currently trying to hide a list in my report by using a conditional block based on a Boolean variable (Yes/No).

The basic idea behind the variable is: "amount A >= 0". Where amount A is a calculated value (amount B - amount C) which returns a number i.e. 17,5.

For example person X has a mobile phone for company use. Based on the companies definition of the work week (in this case mo-fr between the hours of 07:30:00 and 18:00:00) the report splits the bill between during the work week and everything else. This is presented in two separate lists on an aggregation level (such as calls, messages and data).

The total costs for each of these aggregation levels is summarized to calculate the total costs during workweek and everything else. The amount for everything else is "amount B".

The company has a set value (data item), say 5 euro's, which it won't deduct from the user's pay. This is "amount C". Anything above that amount the company won't pay for.

I have a data item in a list (single column and row) which takes amount B and deducts amount C and returns a value. This value is amount A which the user has to pay.

Based on whether amount A is equal or larger then 0 (the Boolean variable) the list should be shown or hidden. In short this is what I want to happen:

If amount A >= 0 then show list if not then hide the list.

The Problem:

When I run the report I get the following error: “An error on or around the position '0'. The variable named “amount A” is invalid.”

What I have tried:

I have duplicated the query for amount A and based the Boolean variable on the data item for amount A in the new query. Because I suspected that by encasing the list within a conditional block it might “frown” upon comparing a value within the block against the variable which determines the blocks own visibility status.

I have tried creating a buffer data item, since I figured something might be going haywire with the comparison between amount A versus the variable since the variable depends on amount A. The buffer data item was located in a duplicate query which returns the same results as amount A. This however generated the same error.

I have tried creating the buffer item in the original query but this generates the same error.

Any help is appreciated and more information will be provided upon request,

-Luhaine

 

[blom0344]

The Boolean expression should something like :

[dataitem] = 'some_expression'

[[ not an if then else !! ]]

If this expression evaluates to true then the value 'Yes' is assigned. When using the render variable in a list,block or page, then you can choose to activate/deactivate the 'Yes'.

Another good site is:

http://www.cognoise.com

Ties Blom

 

[Luhaine]

Tahnks for the reply, I'll check cognoise.com out when I have a chance.

As to your tip, thanks but the boolean is in the proper syntax already. I merely stated what I wanted it to accomplish in relation to the conditional block. Maybe that caused some confusion.

To further clarify, it is currently shaped like this:

[dataitem] >= 'expression'

I even tried:

[dataitem] >= expression

both return the same error when running the report. The settings for the behaviour of the conditional block, as in how to respond to the outcome of the boolean, was already set correctly.

 

[blom0344]

You can hide a list/block/page based on the evaluation of a dataitem that has a single value. Question in your case is which value of Amount A needs to be evaluated?

My experience with conditionally hiding objects is based on - for instance - prompt values. You evaluate a chosen value and decide in the rendering what to do.

I have no idea if your approach is at all possible

Ties Blom

 

[ict2000]

The problem could be caused by Cognos 8 optimisation to remove unused items from the query. To fix, try the following:

1. select the List object in the Properties pane
2. In the Data section, click ... next to Properties
3. Click the query item A then click ok

The problem should be fixed then. If it is not, you might need to repeat the above steps for the Page object.

Cognos has several related KB documents on their site. Just search for the error string.

 

[Luhaine]

I didn't get it to work with the conditional block, despite the tips provided, thanks though

I DID get it to work though by using a render variable.