Aggregate Column

Aggregate Column

Type: aggregate-column  ·  Package: DataTable Activities v1.0.5  ·  Output: number

Computes a summary value over a DataTable column: the sum, the count, the average, the minimum or the maximum. It is the direct way to get totals and metrics from a data set — the total to collect, the number of records, the average of an indicator.

How it works

Applies the given operation to the values of the column and returns a number.

• sum, avg, min and max take every cell that can be converted to a number (with a dot as decimal separator, 1500.50). Empty or non-numeric cells are skipped without error and do not count toward the average.
• count returns the number of rows in the table, without looking at the column content (empty cells are counted too).
• If no cell is numeric (or the table has no rows), sum, avg, min and max return 0.

Required parameters

Parameter	Type	Default	Description
table	DataTable	—	The DataTable.
column	string	—	Name of the column to aggregate.
operation	string	—	Operation: sum · count (row count) · avg (average) · min (minimum) · max (maximum).

Optional parameters

None.

Output

Returns a number (double) with the result. count is also returned as a number (12 → 12.0); use toInt(...) if you need an integer.

Common errors

Message	Cause and fix
'table' must be a DataTable.	table does not evaluate to a DataTable.
'column' is required.	The column name is missing.
Column '…' does not belong to table ….	The column does not exist in the table (.NET message). Check the exact name.
Unsupported operation '…'. Use: sum, count, avg, min, max.	operation is not one of the valid values.

Example

Total and average of sales:

Aggregate Column   table = sales   column = "Amount"   operation = sum   → output: total
Aggregate Column   table = sales   column = "Amount"   operation = avg   → output: average
Log   message = "Total: " + total + " · Average: " + round(average, 2)

Aggregate over filtered rows

To summarize only a subset, filter first and aggregate over the result. For totals per category (e.g. total per customer), use Group By.

Related activities

• Group By — aggregates per group instead of a single global one.
• Filter DataTable — narrow down the rows before aggregating.
• Get Column — get all the column values as a list.