INDEXBY

Returns a value of a specific index within a column, partitioned by the unique values of a separate column

INDEXBY( column, integer, partition column, [sort column] , [ascending])

Indexes a given column when grouped by unique values within a partition column

INDEXBY() is a window function, which performs like INDEX() except partitioned by the unique values of a different column.

Arguments

Argument	Description
column	Column to index
integer	Index of indexed column to ouput
partition column	Column containing unique values
[sort column]	Optional. Column with which to sort partitioned rows by. Defaults to index.
[ascending]	Optional. Enter True to sort in ascending order (default), or False to sort in descending order.

Output

Outputs a given index from each partitioned group within the indexed column

Examples

Let's say that we want to find the first state in each region in a table. We have a table that lists each state and its corresponding region -- by using INDEXBY({State}, 1, {Region}) , we can select the first state for whatever region that state is in.