You need to create Summary field CountOfVendors (or whatever name). On the left SELECT COUNT. Then the field you want to count. Place this field in a sub-summary part of the layout, that breaks on how you want the count, i.e. years.
Thanks for your reply, but my issue wasn't with creating a report, I have that working fine. Rather, it was having a SQL that could "feed" a graph. Based on the severe limitations of FMP SQL's GROUP BY, making it nearly unusable for certain simple reports, I'm going to just create a new table and write a script to populate it with the values (Year, count-by-year-sum) that the graph needs.
So, instead of this taking several minutes, like it should, it will take several hours total (including time already spent).
Update - As I wrote above, I ended up creating a separate FMP table to hold the year and count of items per year from my "many" table implemented as a portal in the layout.
The script to generate the data took about 30 minutes to write (add this time to the 3 or 4 hours yesterday of trying to get the "helper" fields to work with the SQL).
The MySQL query took, MAYBE, 2 minutes (including creating the test table and a few sample data rows).
FileMaker clearly took too much time in this case due to its SQL limitations.
It's also possible that I'm not as proficient in FileMaker as many others since it's not my full-time product of choice.
While in the past, I've been able to "supplement" the FIleMaker's "SQL" limitations with "helper fields" (since FMP won't allow expressions in GROUP BY!!!!). Yet, for this particular case, I couldn't figure out how to do a nested COUNT of a YEAR(datefield). FileMaker would either give me the total number of records in each of the calculated fields or all "1s" - since there was only 1 2010, 1 2011, etc., instead of the counts of dates for each of these years.
I find some things in FMP really fast and easy yet other things, which seem like they should be quick and easy, I find cumbersome and time consuming compared with other database environments.
Since your are counting records, I would have thought (haven't tried it) , that Count (*) would have worked in this query...
Wonder what result you would have gotten if you hadn't used the Count expression in the order by clause but used cnt instead?