I'm sure you can do this easily using SQL syntax.
For instance,

SELECT child.keyfield,count(*) from child where child.keyfield in
(select parent.keyfield from parent) group by 1

>I have a parent table related into a child table
>
>I want to look through all the child records, and there can be thousands of
>child records.
>
>So I was hoping to display a "Record of " message, but there
>is no point in looping through all the child records just to get a
>count.
>
>I was hoping there was some command that would tell me how many records
>match the relation without having to count them.
>
>Thanks