Table.AddIndexColumn

Table

Adds a sequential index column to a table.

Syntax

Table.AddIndexColumn(table as table, newColumnName as text, optional initialValue as nullable number, optional increment as nullable number, optional columnType as nullable type) as table

Parameters

Name	Type	Required	Description
`table`	`table`	Yes	The input table to add an index column to.
`newColumnName`	`text`	Yes	The name of the new index column.
`initialValue`	`number`	No	The starting value of the index (default is 0).
`increment`	`number`	No	The increment between consecutive index values (default is 1).
`columnType`	`type`	No	Optional type annotation for the index column.

Return Value

table — The input table with an additional column containing sequential index values.

Remarks

Table.AddIndexColumn appends a new column with sequential numeric values. By default, the index starts at 0 and increments by 1. Use the optional parameters to start at a different value or use a custom increment.

Index columns are useful for creating a unique row identifier, enabling row-number-based joins, or preserving original row order before operations that may reorder the data.

Examples

Example 1: Add a 1-based index

Table.SelectColumns(
    Table.AddIndexColumn(Table.FirstN(Sales, 5), "RowNum", 1, 1, Int64.Type),
    {"RowNum", "CustomerName", "Product"}
)

Result

	RowNum	CustomerName	Product
1	1	Alice	Widget A
2	2	Bob	Gadget B
3	3	Charlie	Widget C
4	4	Alice	Gadget D
5	5	Diana	Widget A

Compatibility

✓ Power BI Desktop✓ Power BI Service✓ Excel Desktop✓ Excel Online✓ Dataflows✓ Fabric Notebooks