[AccessD] SQL count distinct problem

Assume a table with vendor, inv amt and check number. There may be multiple
records for the vendor with the same check number. If I want to determine
the total amt paid to a vendor and the number of checks written to him a
simple groupby query will not do since the count function will count the
number of occurrences not number of distinct checks. COUNT(DISTINCT(CHKNO)
works in a pass through query on the AS400 but not in Jet SQL. What is the
equivalent Jet SQL to determine the number of distinct checks written per
vendor? TIA
Jim Hale

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