Table.DuplicateColumn

Table

Duplicates a column in a table with a new name.

Syntax

Table.DuplicateColumn(table as table, columnName as text, newColumnName as text, optional columnType as nullable type) as table

Parameters

Name	Type	Required	Description
`table`	`table`	Yes	The input table.
`columnName`	`text`	Yes	The name of the column to duplicate.
`newColumnName`	`text`	Yes	The name of the new duplicate column.
`columnType`	`type`	No	Optional type for the new column.

Return Value

table — The input table with a new column that is a copy of the specified column.

Remarks

Table.DuplicateColumn creates a copy of an existing column with a new name. This is useful when you want to transform a column but also keep the original values — duplicate first, then transform the copy.

The new column is appended to the end of the table. Use Table.ReorderColumns if you need it in a specific position.

Examples

Example 1: Duplicate a column for transformation

Table.SelectColumns(
    Table.DuplicateColumn(Table.FirstN(Sales, 3), "Product", "OriginalProduct"),
    {"OrderID", "Product", "OriginalProduct"}
)

Result

	OrderID	Product	OriginalProduct
1	1	Widget A	Widget A
2	2	Gadget B	Gadget B
3	3	Widget C	Widget C

Compatibility

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