Values are Lower than Expected after Joining Tables
Published: 16 Oct 2017 Last Modified Date: 15 Oct 2018
When connecting to multiple tables from a data source with table joins, the values in Tableau Desktop may be lower than expected.
Add matching values to the linking fields in both tables in the data source.
Rearrange tables in the join. The table that contains all possible values in the linking field should be the leftmost table in the join when the join type is Left Outer Join. If neither table contains all possible values, this option will not work.
Use a Full Outer join. A Full Outer Join will include all records from both tables even when there is no matching values in the linking fields. Please note, data for which there were no matching values in the linking fields will not be related. Also note, the Full Outer join type is not available for all data sources.
Some join types exclude data when there are no matching values in the linking fields. To learn more about how table joins work, please see Join Your Data