distinct

distinct(T.‘a) 🡒 number, aggregator

The aggregator indicates how many distinct elements there are. Two elements a and b are considered identical if a == b.

Example:

table T = with
  [| as A, as B |]
  [| 0,   "a"   |]
  [| 0,   "a"   |]
  [| 0,   "b"   |]
  [| 1,   "b"   |]
  [| 1,   "c"   |]

table G[gdim] = by T.B

where T.B != "c"
  show table "" a1b4 with
    gdim
    distinct(T.A)
    group by gdim

The aggregator distinct supports boolean, date, number, text and enum types. It returns 0 on empty groups.

The use of distinct is not recommended for number and text for large datasets, as this may cause performance problems. If you only need an approximation of the number of distinct values, use distinctapprox instead.

If the number of distinct values is not relevant, so much as whether it is 1 or more than 2, use the much faster aresame instead.

See also