countBy

countBy returns the number of rows for each group.

Syntax

table.countBy(countColumnName)
table.countBy(countColumnName, groupByColumns...)

Parameters

Parameter	Type	Description
countColumnName	String	The name of the output column containing the count.
groupByColumns	String...	The column(s) by which to group data. `NULL` returns the total count of rows in the table. `"X"` will output the count of each group in column `X`. `"X", "Y"` will output the count of each group designated from the `X` and `Y` columns.
groupByColumns	ColumnName...	The column(s) by which to group data. `NULL` returns the total count of rows in the table. `"X"` will output the count of each group in column `X`. `"X", "Y"` will output the count of each group designated from the `X` and `Y` columns.
groupByColumns	Collection<String>	The column(s) by which to group data. `NULL` returns the total count of rows in the table. `"X"` will output the count of each group in column `X`. `"X", "Y"` will output the count of each group designated from the `X` and `Y` columns.

Returns

A new table containing the number of rows for each group.

Examples

In this example, countBy returns the number of rows in the table and stores that in a new column, Count.

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.countBy("Count")

In this example, countBy returns the number of rows in the table as grouped by X and stores that in a new column, Count.

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.countBy("Count", "X")

In this example, countBy returns the number of rows in the table as grouped by X and Y, and stores that in a new column Count.

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.countBy("Count", "X", "Y")

countBy

Syntax

Parameters

Returns

Examples

Related documentation