Working with duplicate values

You can work with duplicate sets of values through transformations that can remove duplicates from your data or filter your data to show duplicates only, so you can focus on them.

Warning

Power Query is case-sensitive. When working with duplicate values, Power Query considers the case of the text, which might lead to undesired results. As a workaround, users can apply an uppercase or lowercase transform prior to removing duplicates.

For this article, the examples use the following table with id, Category, and Total columns.

Initial sample table.

Remove duplicates

One of the operations that you can perform is to remove duplicate values from your table.

  1. Select the columns that contain duplicate values.

  2. Go to the Home tab.

  3. In the Reduce rows group, select Remove rows.

  4. From the drop-down menu, select Remove duplicates.

    Remove duplicates.

Warning

There's no guarantee that the first instance in a set of duplicates will be chosen when duplicates are removed.

Remove duplicates from multiple columns

In this example, you want to identify and remove the duplicates by using all of the columns from your table.

Initial table with duplicates in multiple columns.

You have four rows that are duplicates. Your goal is to remove those duplicate rows so there are only unique rows in your table. Select all columns from your table, and then select Remove duplicates.

The result of that operation will give you the table that you're looking for.

Final table with duplicates removed from all columns.

Note

This operation can also be performed with a subset of columns.

Remove duplicates from a single column

In this example, you want to identify and remove the duplicates by using only the Category column from your table.

Initial table with duplicates in the Category column.

You want to remove those duplicates and only keep unique values. To remove duplicates from the Category column, select it, and then select Remove duplicates.

The result of that operation will give you the table that you're looking for.

Final table with duplicates removed from the Category column.

Keep duplicates

Another operation you can perform with duplicates is to keep only the duplicates found in your table.

  1. Select the columns that contain duplicate values.

  2. Go to the Home tab.

  3. In the Reduce rows group, select Keep rows.

  4. From the drop-down menu, select Keep duplicates.

    Keep duplicates.

Keep duplicates from multiple columns

In this example, you want to identify and keep the duplicates by using all of the columns from your table.

Initial table for keeping duplicates from multiple columns.

You have four rows that are duplicates. Your goal in this example is to keep only the rows that are duplicated in your table. Select all the columns in your table, and then select Keep duplicates.

The result of that operation will give you the table that you're looking for.

Final table with only duplicated rows from multiple columns.

Keep duplicates from a single column

In this example, you want to identify and keep the duplicates by using only the id column from your table.

Initial table for keeping duplicates from a single column.

In this example, you have multiple duplicates and you want to keep only those duplicates from your table. To keep duplicates from the id column, select the id column, and then select Keep duplicates.

The result of that operation will give you the table that you're looking for.

Final table with only duplicated rows from a single column.

See also

Data profiling tools