Get distinct comma separated list of values in Crystal Reports Footer

I have a report with many detail lines. For example:

Horse 123
Cow 453
Pig 123
Sheep 546

I need to put a summary at the bottom of the report, which in this case would read:

123, 453, 546

A comma separated list of values, WITHOUT repeats.

I don't care if I need to use sql expressions, Crystal Reports code, or vb code to do it, but I have to be able to print a comma separated list of distinct values.

I have tried doing this with an sql expression, and it will not work in the report but will from SQL Query Analyzer directly on the DB. Can a Crystal Reports sql expression field use the full range of SQL query commands? Or is it just a subset? What are the limits? Help on any of these questions would be much appreciated. I'm using Crystal Reports 10, btw.

To do that, you have to Group your data and create 2 formulas:

The first one, let's say @comma_field:

Code:

---

whileprintingrecords;
stringvar names;
names := names & ", " & {table.field};

---

Place it in your GroupHeader section which you can suppress; the formula will return you next:
, Jules, Christina, Paul


and the secondformula, let's call it @final (or whatever you like):

Code:

---

whileprintingrecords;
stringvar names;
Mid(names, 3);

---

Place it in your Report Footer section.