Question

How do I merge two datasets while ensuring that duplicate rows are handled properly?
I am working on a Power BI report where I need to merge two datasets with overlapping rows. It is crucial to handle duplicate rows correctly to avoid inflating data during the merge process. What is the best approach using Power Query or DAX to ensure accurate and efficient dataset merging?

Answer 1

To merge two datasets and take care of duplicates in Power BI

Remove Duplicates Before Merging:

In Power Query, the Remove Duplicates function should be applied to each dataset according to the relevant columns.

Merging Datasets:

From then on, in Power Query, Home > Merge Queries, choosing the appropriate join (say, Left Outer, Inner).

Remove Duplicates After Merging:

Use Remove Duplicates again if needed, or aggregate duplicate rows using Group By.

Optional DAX Approach:

After the merging, you may remove duplicates with DAX using DISTINCT or SUMMARIZE.