Grouping (nesting) filter conditions

Grouping (nesting) filter conditions

You can group two or more conditions as a single unit within the list of conditions. The grouped conditions are evaluated before the conditions outside the group.

A group may contain multiple nested levels of sub-groups, but each sub-group must be completely within its parent group. When a filter contains multiple levels of grouping, the innermost group is evaluated first.

For example, if you have a number of computers, with some running Windows XP and some running Windows 2000, and apply the following filter:

	 OperatingSystem.Name	=   Windows XP		AND 
	 PhysicalMemory.Capacity   >   512 Mb			OR 
	 OperatingSystem.Name	=   Windows 2000		AND 
	 PhysicalMemory.Capacity   <   256 Mb

Without grouping, this filter returns only the Windows 2000 computers that have less than 256 Mb of memory. The Windows XP computers that were selected with the first two conditions are not returned as they do not satisfy the fourth condition.

To make the filter return the Windows XP computers that have over 512 Mb of memory and the Windows 2000 computers that have less than 256 Mb of memory, you need to group each OperatingSystem condition with the corresponding PhysicalMemory condition. This grouping is shown below:

  (	OperatingSystem.Name	=   Windows XP		AND 
	 PhysicalMemory.Capacity   >   512 Mb		 )  OR 
  (	OperatingSystem.Name	=   Windows 2000		AND 
	 PhysicalMemory.Capacity   <   256 Mb		 )

The grouping is indicated in the list of conditions as follows:

( in the (... column	The first condition in the group.
) in the ...) column	The last condition in the group.

When you delete conditions from a group, the grouping is automatically adjusted according to the remaining group start and end conditions. The grouping adjustment depends on whether the deleted conditions are at the start or end of the group, or in the middle:

Conditions deleted from within a group, and no end-of-group conditions deleted.		Grouping is preserved on remaining conditions.
Condition deleted from start or end of a group.		Grouping is removed from remaining conditions. If a deleted condition is the start or end of two or more nested groups, all nested groups are ungrouped.

To group (nest) filter conditions

In the Properties for <Filter name> window, in the list of conditions, select the conditions that you want to group.

You can select all the conditions, or just the first and last conditions. Any unselected conditions between the selected conditions are automatically included in the group.

Click Group.

The grouping is indicated in the list of conditions.

If you need to undo any grouping, select all the conditions in the group, or the first or last condition of the group, then click Ungroup.

If the selected condition is the first or last for two or more groups, the outermost group is ungrouped.