# Rollup

Aggregate and look up data in a second workbook data element.

To learn how to apply the Lookup and Rollup functions without directly using the formula bar, visit Add Columns via Lookup.

## Usage

`Rollup(formula, local key 1..., external key 1..., local key 2..., external key 2..., ...)`

**formula** [required] The formula to compute (or the target column to reference) for the row in the target element

**local key** [required] The column to use as a join key in the local data element

**external key** [required] The column to use as a join key in the target data element

## Examples

### Example #1

Rollup(Sum([Sales Amounts/Sales Amount]), [Order Number], [Sales Amounts/Order Number])

Data is inserted into the *Orders *table’s **[Calc]** column from *Sales Amount* table’s **[Sales Amount]** column.

The function’s *formula* parameter uses the Sum function to aggregate values from the *Sales Amount* table’s **[Sales Amount]** column.

These two tables are joined using a single set of join keys: *Orders’ ***[Order Number]** column is joined with *Sales Amounts’ ***[Order Name]** column.

## See Also