creating dynamic analysis studio type reports in report studio

Proven Practice

Creating Dynamic Analysis Studio Type Reports in Report Studio

Part-2

Product(s): Report Studio

Area of Interest: Report Design

Creating Dynamic Analysis Studio Type Reports in Report Studio Part-2

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Copyright

Copyright © 2008 Cognos ULC (formerly Cognos Incorporated). Cognos ULC is an IBM Company. While every attempt has been made to ensure that the information in this document is accurate and complete, some typographical errors or technical inaccuracies may exist. Cognos does not accept responsibility for any kind of loss resulting from the use of information contained in this document. This document shows the publication date. The information contained in this document is subject to change without notice. Any improvements or changes to the information contained in this document will be documented in subsequent editions. This document contains proprietary information of Cognos. All rights are reserved. No part of this document may be copied, photocopied, reproduced, stored in a retrieval system, transmitted in any form or by any means, or translated into another language without the prior written consent of Cognos. Cognos and the Cognos logo are trademarks of Cognos ULC (formerly Cognos Incorporated) in the United States and/or other countries. IBM and the IBM logo are trademarks of International Business Machines Corporation in the United States, or other countries, or both. All other names are trademarks or registered trademarks of their respective companies. Information about Cognos products can be found at www.cognos.com

This document is maintained by the Best Practices, Product and Technology team. You can send comments, suggestions, and additions to [email protected] .


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Contents

1 INTRODUCTION ............................................................................................ 4

1.1 PURPOSE ............................................................................................................4 1.2 APPLICABILITY .....................................................................................................4

2 EVALUATION OF THE PROBLEM.................................................................... 4

2.1 ENABLING DRILL-UP AND DRILL-DOWN .......................................................................4 2.2 BREAKING DOWN THE DRILL BEHAVIOUR .....................................................................7 2.3 FIXING THE DRILL BEHAVIOUR ..................................................................................8 2.3.1 Step 1 ..............................................................................................................8 2.3.2 Step 2 ............................................................................................................ 10 2.3.3 Step 3 ............................................................................................................ 12 2.3.4 Step 4 ............................................................................................................ 13 2.3.5 Step 5 ............................................................................................................ 14 2.3.6 Step 6 ............................................................................................................ 14 2.3.7 Step 7 ............................................................................................................ 15 2.4 EXAMINING THE BEHAVIOUR OF MORE SUBTOTAL ......................................................... 16 2.5 MAKING “MORE SUBTOTAL” DYNAMIC ....................................................................... 16


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1 Introduction

1.1 Purpose

This document is intended to help anyone who has a requirement to use Report Studio to perform some of their OLAP type reporting, yet still retain some of the Analysis Studio type functionality. Only a couple of Analysis

Studio reporting techniques are created in this document, and it is intended as an example of what can be done in Report Studio. This is part-2 of the entire technique in which we will take the previously built report and make it more dynamic by adding drill-up and drill-down functionality to the report as well as making the “More” calculation visible only if the number of members in the level warrant the data item to appear. If you have not already done so it is strongly recommended that you read part-1 of this technique. An advanced knowledge of OLAP and report design for IBM Cognos 8 is

recommended to fully understand the techniques in this document.

1.2 Applicability

This document was created using IBM Cognos 8 MR2 specifically the Great Outdoors Company sample cube that comes with the product. At the time the document was created all techniques were validated and supported.

2 Evaluation of the Problem

2.1 Enabling Drill-Up and Drill-Down

To enable drill-up/drill-down open the report created in part-1 and then select “Data” from the menu, then “Drill Behaviour” (diagram 1). In the dialog box

that appears ensure that the “Allow drill-up and drill-down” checkbox is selected (diagram 2) and press “OK”. Run the report and then drill down on

Camping Equipment. Notice the results (diagram 3). They don’t look quite right. First, the number of visible items exceeds the value of 2 which we set when creating the previous report. Second, the total for “More Subtotal” and

“Total” didn’t change when drilling down. Let’s examine why these things happened.


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Diagram 1

Diagram 2


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Diagram 3


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2.2 Breaking Down the Drill Behaviour

A couple of things happened that were unexpected when drilling down on our previous report. First the number of visible items changed from what we

enabled in the report. We originally set the number of items to be displayed to 2, with an overflow of 2, however when drilling down on “Camping Equipment” we saw all 5 members at that level. To fully understand why this happened let’s break down the calculations that were used to create that data item.

If you examine the “Products Displayed” calculation you should see that its syntax is:

_firstfromset([Full Members List],2,2)

[Full Members List] is another data item which is used in the _firstfromset function. Drill-up/Drill-down should not impact this particular calculation, so the issue must reside in the “Full Members List” data item. If you examine

the “Full Members List” data item you’ll see that its syntax is:

children([Products])

When you drill down into the “Camping Equipment” member the above expression gets converted from children([Products]) to

children([Camping Equipment]), and this causes problems with the “Products Displayed” data item when drilling down. The context gets lost, when drilling

down and as a result the report doesn’t look the way we would expect it to.

This behaviour is a little more visible with the “More Subtotal” and “Total” data items don’t change in value when drilling down. The reason for this is that like the “Products Displayed” data item the context for the calculation doesn’t change when drilling down. For example, the “Total” data item was created using

total(currentMeasure within set [Full Members List]). Remember

[Full Members List] at the time the report is first run, contains the members which are the children of the “Products” root level. This is group then used in the “More Subtotal” and “Total” data items to calculate the totals. When we

drill down the “Full Members List” data item which is actually children([Products]), becomes static in the “Products Displayed”,

“More Subtotal”, and the “Total” calculations so that each is using the children of “Products” instead of the children of “Camping Equipment” within

their respective calculations.


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2.3 Fixing the Drill Behaviour

Now that we understand why the drill-up/drill-down worked the way it did, we now need to fix it. To do this we need to define a set of

“Member Sets” that will help to carry the context of where we are in the cube into each of the calculations needed in this report.

2.3.1 Step 1

Enable Member Sets in Report Studio by selecting the query from the “Query Explorer” pane window, and then change the properties of the “Define Member Sets” attribute to Yes (diagram 4). You should now see a new tab

when looking at the query itself (diagram 5).

Diagram 4


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Diagram 5

2.3.2 Step 2

Select the “Member Sets” tab in the query view. We need to drag the data item which is at the root of the behaviour, in our case its “Full Member List”. Drag that “Full Member List” data item into the Member Set pane, then change the “Name” property to something new. In this case “Full Member List ms” was used (diagram 6), you can use any name as long as it’s different from the actual data item. This avoids name conflicts in the report.


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Diagram 6


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2.3.3 Step 3

Now we drag all the data items in our report which are dependant on the “Full Member List” data item, and place them on top of the Member Set that

we just created (diagram 7). It is critical that you ensure that the mouse pointer is resting directly on top of the member set we created (diagram 8). If it’s too high you will see a thin black line above the member set (diagram 9), and if it’s too low you will see a thin black line below the member set (diagram 10). This should create a tree structure with the Member Set we created at the root and the 3 data items dependant on the “Full Member List” data item as its children (diagram 11).

Diagram 8

Diagram 9

Diagram 10


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Diagram 11

2.3.4 Step 4

Next follow the steps in section 2.1 “Enabling Drill-Up and Drill-Down”, and ensure the “Allow drill-up and drill-down” check box is enabled then select the “Advanced tab”.


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2.3.5 Step 5

Next select the “Full Member List” data item and change the “Drill-up behaviour” and the “Drill-down behaviour” to both be “Replace Expression”

(diagram 12). This essentially will change the expression in every instance to the new value after you drill-up or drill-down. For example when you first run the report the expression is children([Products]), and when you drill-down on Camping Equipment the expression is not changing. This will force the expression to change in all data items to be

children([Camping Equipment]).

Diagram 12

2.3.6 Step 6

Repeat Step 5 for the “Products Displayed”,” Total”, and “More Subtotal” data items using “Preserve” instead of “Replace Expression” for the drill-up or drill-down behaviour (diagram 13). Press “OK” when done.

Diagram 13


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2.3.7 Step 7

Run the report and drill down on “Camping Equipment”, notice that the “More Subtotal” and the “Total” data items change to reflect the level you have now drilled down into (diagram 14).

Diagram 14


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2.4 Examining the Behaviour of More Subtotal

Run the report and drill-down on “Golf Equipment”, then drill-down on

“Putters”. Notice that the number of visible items shown is four, and the “More Subtotal” data item is now displaying a value of 0 (diagram 15). If you remember from part-1 we defined the “Products Displayed” member to display two members, with an over flow of two. What this essentially does is display two members up to four (two as the base with an overflow of two). So in effect will see all the members in a level if there are four or less. Anything above four will display only two.

Diagram 15

2.5 Making “More Subtotal” Dynamic


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So now that you understand how the _firstfromset() function affects the number of visible items how do we set the “More Subtotal” to appear only if it

is needed.

Step 1

Select the query from the “Query Explorer” tab, and insert a new data item object from the “Insertable Objects” of the “Toolbox” tab. In the “Expression Definiton” pane enter the following syntax _remainderset( (diagram 16).

Diagram 16


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Step 2

Next from the “Data Items” tab of the “Available Components” drag the “More Subtotal” data item to the right side of the ‘(‘ in the expression. Next

add a comma and then drag the “Full Members List” data item to the end of the expression. End the expression by entering the following “,4)”

(diagram 17). Your full expression should look like the one below.

_remainderset([More Subtotal],[Full Members List],4)

Validate the expression then press “OK”.

Diagram 17


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Step 3

The last step is to rename the data item from “Data Item 1” to “More”. Then select “Page 1” from the “Page Explorer”. You need to replace “More Subtotal” with the newly created “More” data item. To do this highlight

“More Subtotal” in the report and choose “Cut” from the “Edit” menu. Next drag the “More” data item so that it is dropped between “Products Displayed”

and “Total” (diagram 18). The final piece of the puzzle is to change the expression definition of “Products Displayed” to be “_firstfromset([Full Members List],2,0)” instead of “_firstfromset([Full Members List],4,0)”. This

will only display four members with no overflow.

This time when running the report and drilling-down into “Golf Equipment”

and then “Putters” you’ll notice that the “More Subtotal” now disappears instead of showing a value of 0 (diagram 19).

Diagram 18


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Diagram 19

creating dynamic analysis studio type reports in report studio

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