LIMIT result for paging

[Bob johnston]

I make a RecordSet with Inner Join from 2 tables.

Table 1 contains product information.

Table 2 contains package sizes and price information

Since there are several different package sizes of some products, 1 single product can return this to the RecordSet

catalogID;"descr";packsize;"packtype";price
334;"Angelique";10;"L";59
334;"Angelique";25;"A";119
334;"Angelique";50;"B";199
334;"Angelique";250;"C";639

I run through the RecordSet and present the data in a web page with a predefined number of products per page. That is working perfectly well for page number 1.
The above example for article nr 334 will be presented as one product

However - I have a paging function that divides the RecordSet into pages with the predefined number of RecordSet posts per page.

Is there at all a way to call the database in a way that returns how many uniqe catalogID the RecordSet contains?