Your question intrigued me as I never use the group selection in the group expert (or so I thought).

I assumed it was just another AND statement you could insert group conditions on and keep track of them there but I just tested it and it did something a little different than I expected.

Usually you can run into selection problems on summary data because they "must be evaluated later" basedo nthe order that Crystal does itdata reads, formula reads and summarizing.

My simple test came up with to things. I was able to filter the data based on a DistinctCount at my group level when putting the condition in the group Selection but got the evaluate later error when placing the Distinct count in the Record Selection portion even though the syntax was the exact same.

Also very oddly All of my groups showed up in the group "tree" with no data under the groups that did not meet my group select condition rather than omitting them from the report completely (this test had a left join in it so that may have impacted the results).

 

Noted also when you have a field highlighted (actively selected in the report) and you click on the select expert button it will default to that field and give you options to filter on it.  Anice short cut i use for basic selection criteria. However this time I noticed if you select a group or report summary field and clcik on the Select Expert it will default to having the Group selection criteria highlighted. Hence I have done this filtering on some grouped criteria before but had not noticed this was going into the group selection portion of the select expert because that is hidden unless you move into the FOrmula portion.

Basically this appears to be a way to do selections based on Group summary criteria that normally would cause you problems based on evauation order of things. If you ever want to exclude a grouping of data based on a SUM or count or distinctcount etc. it must go into this part of the select expert. It appears to act as an AND with the Record Selection criteria if you are using both parts.

Hope this helps and thanks for asking the question!

 

Group Selection formulas are used when you don't want to print all of the groups in a report, but still want all records displayed for the groups that are left. This usually means you are selecting only certain group names or using a sum or count (or any summary field). For example, you want to display all attendance history for specific students (Alphakey would be the group.  An example of selection by group name, but this would also work as a record selection) or all the attendance history for students who have missed more than 10 days (this would be a group selection by a summary field). In the Fiscal world, you could use a group selection to show all vendors that were paid more than $20,000. In HR you might use a group selection to show detailed days missed for employees who missed more than 5 days.

I think the formula listed is from the Voc report. In the Voc report, it originally showed the Voc history for all active students, but our Voc Director only wants to see students who took a Voc course during the current school year. We can use record selection to only show courses taken during the current school year by adding a formula to the record selection. Unfortunately, this will also prevent any historical Voc classes from being displayed.

If we add a sum that count how may voc courses a student has taken for the current year and add a formula to the group selection expert, we can only show the students who have taken at least 1 voc course this year while still displaying all of the voc history for these students.

The caveat to group selections in our environment is that they are evaluated client side. Record selections are usually done by the database server so they run faster. With group selection formulas, all of the groups are downloaded to your computer (or the metaframe server) before crystal decides which ones need to be displayed.

The short version of that-- If the report will work with a record selection formula instead of the group selection formula, it will run much quicker.

That probably didn't make any sense- but there is also an explanation on page 176 of the manual. https://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/50c466a0-7c64-2b10-9697-bd3ac4a62bf6