BIRT grouping how to

I'm new to BIRT and looking for some help. I've already set up a basic grouping that for every "Computer Host" shows a table with the current virtual running and its operative system.

In BIRT I have a table with a group "Hosts" (data item). Then I have the data items "Virtual Machinese Name" and the data item "OSnameOfVM".

example:

"Name of Host"
VMNAME__:OS NAME
Virutal1:Win开发者_Go百科dows
Virutal2:Linux
Virutal3:Winows
Virutal4:Linux 

This example I've succesfully set up, and it works with grouping.

THE PROBLEM:

What I want to add is a summary in the form of a table (or whatever report item that would be most suited for this) for each group. This extra "summary table" should list each operative system once (for that particulair table) and then count it.

example continue:

"Name of Host"
VMNAME__:OS NAME
Virutal1:Windows
Virutal2:Linux
Virutal3:Winows
Virutal4:Linux

Summary Table
Windows: 2
Linux: 2

I did try to create a data cube to solve this. But it showed up in the end of the report and became a global summary for all tables. (well that was expected I guess.)

I hope I have provided enough information for this problem.

Help appriciated, thanks in advance =)

You should be able to create and populate the summary table using the built-in aggregation tool. On the Control palette look toward the bottom for "Aggregation". From there you can set up your aggregation data items. In your case probably a count on the OS data item.

Then to add them to the report, you can move the data item itself anywhere you want in a given table. TO avoid it repeating (and to ensure it can see all the data in a given group) you would probably add a summary table to the group footer, and then add your aggregations to that summary table.

You have to create a table, bind it to your data set, add a group by "OS NAME". [OS NAME] Data element will appear into the group header row. Then add an Aggregation cell (with COUNT function) in the same row.