Comparing Matching and Non-Matching Records Across Blended Data Sources

Published: 03 May 2014
Last Modified Date: 21 Aug 2023

Question

How to compare blended data sources to classify matching and non-matching records.

Environment

Tableau Desktop
Data Blending
2 Data Sources with Identical Data Structures

Answer

Go to Analysis > Create Calculated Field.

Name the calculated field and in the Formula field, enter the following:

IF ATTR([<Primary Data Source Field to Compare>]) = ATTR([<Secondary Data Source Field to Compare>]) THEN 'Same' ELSE 'Different' END

Click OK.
Drag the calculated field to the Color shelf on the Marks card to create a view that shows which fields match and which fields are different between the two data sources.

Note:
The primary data source is indicated with a blue check mark, any secondary data sources and fields from secondary data sources have an orange check mark.

Data blending at a glance

Additional Information

For more accuracy, include more comparison clauses to represent more common fields between the two data sources. For example:

IF ATTR([<Primary Data Source Field to Compare>]) =
ATTR([<Secondary Data Source Field to Compare>]) 
AND
ATTR([<Second Primary Data Source Field to Compare>]) = ATTR([<Second Secondary Data Source Field to Compare>])
THEN 'Same' ELSE 'Different' END