The aggregate functions a query may ask for.
count with no field counts rows; with a field it counts the rows where that field is present. countDistinct counts the field's different values — "how many carriers", where one carrier appears on several rows.
count
countDistinct
The aggregate functions a query may ask for.
countwith no field counts rows; with a field it counts the rows where that field is present.countDistinctcounts the field's different values — "how many carriers", where one carrier appears on several rows.