When you preview a report in Crystal the left side of the screen should show you the “group tree”.  This lists all of the groups in the report.  It also allows you to go directly to the first page of any group, just by clicking on that value in the tree.

But a few times a year I work with a report where the group tree is in “Only Drill-Down” mode (ODD). In this mode, every entry in the group tree is accompanied by the drill-down indicator (a magnifying glass).  Clicking on an entry no longer takes you to the first page of that group but instead it takes you to a drill-down tab for that group. To get to the correct page for a group I have to do a search.

It is a minor irritation so I have let it go for years.  It just never seemed worth the time to figure out why some reports do this. But I figured it had something to do with the Hide/Suppress properties of the Group Header (GH) and Group Footer (GF). This week I got an ODD report from a customer, and so I decided to test all the combinations and see which ones were ODD.

I found four rules that control this behavior:

• If either the GH or the GF is visible you get the normal group tree.
• If both of those sections are suppressed you get the normal group tree.
• If both of those sections are hidden you get the ODD behavior.
• If one of those two sections is hidden and the other is suppressed you get the ODD behavior.

I can’t explain the reasoning behind this pattern (or even the purpose for the ODD behavior) but at least now I know how to change it when I see it.