AggDistinct
AggDistinct
returns an aggregator that computes a set of distinct values within an aggregation group, for each input column.
Syntax
AggDistinct(includeNulls, pairs...)
AggDistinct(pairs...)
Parameters
Parameter  Type  Description 

includeNulls  boolean  If 
pairs  String...  The source column(s) for the calculations.

If an aggregation does not rename the resulting column, the aggregation column will appear in the output table, not the input column. If multiple aggregations on the same column do not rename the resulting columns, an error will result, because the aggregations are trying to create multiple columns with the same name. For example, in table.aggBy([agg.AggSum(“X”), agg.AggAvg(“X”)])
, both the sum and the average aggregators produce column X
, which results in an error.
Returns
An aggregator that computes a set of distinct values, within an aggregation group, for each input column.
Examples
In this example, AggDistinct
returns the distinct set of values of Y
as grouped by X
. includeNulls
is true
and null values are included.
import static io.deephaven.api.agg.Aggregation.AggDistinct
source = newTable(
stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", null),
stringCol("Y", "M", "N", null, "N", "P", "M", null, "P", "M"),
intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)
result = source.aggBy([AggDistinct(true, "Y")], "X")
 source
 result
In this example, AggDistinct
returns the distinct set of values of Y
as grouped by X
. includeNulls
is false
and null values are ignored.
import static io.deephaven.api.agg.Aggregation.AggDistinct
source = newTable(
stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", null),
stringCol("Y", "M", "N", null, "N", "P", "M", null, "P", "M"),
intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)
result = source.aggBy([AggDistinct(false, "Y")], "X")
 source
 result
In this example, AggDistinct
returns the distinct set of values of Y
(renamed to Z
), as grouped by X
. includeNulls
is true and null values are included.
import static io.deephaven.api.agg.Aggregation.AggDistinct
source = newTable(
stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", null),
stringCol("Y", "M", "N", null, "N", "P", "M", null, "P", "M"),
intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)
result = source.aggBy([AggDistinct(true, "Z = Y")], "X")
 source
 result
In this example, AggDistinct
returns the distinct set of values of Y
(renamed to Z
), as grouped by X
. includeNulls
is false
and null values are ignored. Also, AggLast
returns the last Number
integer, as grouped by X
.
import static io.deephaven.api.agg.Aggregation.AggDistinct
source = newTable(
stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", null),
stringCol("Y", "M", "N", null, "N", "P", "M", null, "P", "M"),
intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)
result = source.aggBy([AggDistinct(false, "Z = Y")], "X")
 source
 result