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Alteryx Designer Knowledge Base

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Tool Mastery | Union

Community Data Engineer
Community Data Engineer
Created on

Union.pngThis article is part of the Tool Mastery Series, a compilation of Knowledge Base contributions to introduce diverse working examples for Designer Tools. Here we’ll delve into uses of the Union Tool on our way to mastering the Alteryx Designer:


The Union Tool, the aptly named join category tool with DNA on it, accepts multiple input streams of data and combines them into one, unified, data stream. Whereas the Join Tool combines datasets horizontally (either by a record ID or record position), the Union Tool combines datasets vertically. Not unlike how two nucleic acid strands are unified to form the double helical DNA.


We know, great puns are in our DNA.


The Union Tool has a handful of great applications besides side-stitching punchlines, too. Check them out below:


  • Stacking records

Have common fields in multiple datasets? Stack them into a single stream with the Union Tool by field name, position, or with manual arrangement:


stacking like records.PNG


Don't worry - your datasets don't have to have identical. Any uncommon fields will be at the end of the table, with any fields that are not in a given dataset being populated with null values.


  • Creating different joins

The Alteryx Join Tool has 3 outputs:


alteryx joins.PNG


These look like:




If you’re used to SQL joins, these are the left, inner, and right joins, respectively. The Union Tool allows you to effortlessly combine these Join outputs (shaded areas above) to create other, more complex, SQL join configurations like the ones below:




  • Combining reporting elements vertically

Simply take your reporting elements and specify an Output Order in the Union Tool to stack them vertically - without creating a single reporting element from the combination like the Layout Tool does:




See the attached workflow, Union.yxmd, for the stack, join, and reporting examples shown above!


By now, you should have expert-level proficiency with the Union Tool! If you can think of a use case we left out, feel free to use the comments section below! Consider yourself a Tool Master already? Let us know at if you’d like your creative tool uses to be featured in the Tool Mastery Series.


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How can I add a column to output to indicate source of input data ( such as from 1st source or second or third etc. )?