Table.RemoveDuplicates

Table

Removes duplicate rows from a table based on one or more key columns.

Syntax

Table.RemoveDuplicates(table as table, optional columns as any, optional equationCriteria as any) as table

Parameters

Name	Type	Required	Description
`table`	`table`	Yes	The input table to deduplicate.
`columns`	`any`	No	A column name or list of column names to check for duplicates. If omitted, all columns are compared.
`equationCriteria`	`any`	No	Optional comparer function for custom equality logic.

Return Value

table — A table with duplicate rows removed, keeping the first occurrence of each unique key.

Remarks

Table.RemoveDuplicates keeps the first occurrence of each unique combination of key column values and removes subsequent duplicates. When no columns are specified, the entire row is compared.

If you need to control which duplicate row is kept (e.g., keep the most recent or the lowest price), sort the table first with Table.Sort and then wrap the result in Table.Buffer before calling Table.RemoveDuplicates. Without Table.Buffer, the sort order is not guaranteed to be preserved, which means you may not keep the intended row.

Examples

Example 1: Remove duplicate customers

Table.RemoveDuplicates(Sales, {"CustomerName"})

Result

	OrderID	CustomerName	Product	Category	UnitPrice	Quantity	OrderDate	Region
1	1	Alice	Widget A	Widgets	25	4	1/15/2024	East
2	2	Bob	Gadget B	Gadgets	50	2	1/18/2024	West
3	3	Charlie	Widget C	Widgets	15	10	2/1/2024	East
4	5	Diana	Widget A	Widgets	25	6	3/5/2024	West

Example 2: Remove duplicates by multiple columns

Table.SelectColumns(
    Table.RemoveDuplicates(Sales, {"Category", "Region"}),
    {"CustomerName", "Category", "Region"}
)