Sometimes you need a file to grow as your data grows but you don't want to append the new data in the same column, instead, you want it to be in to be in a new column. You can use the build historical data step to achieve this.
The image on the left represents the sales by month by model of car (left). We want to create a historical sales report (right) that shows how these models have sold over multiple months.
1. Create a new action step by right-clicking on a group and then selecting "Add action step":
2. Under "Manipulating Data" select "Multiple file manipulations" and then click on "Add the selected step to my process":
3. Add a new instruction search for "build". Select "Build historical data":
4. Configure the build historical data step:
4.1. Link the source file, this is the file that is updated in each period. Below, sales for January:
4.2. Link the target file, this will store the historical data. The range should be the column where the items are(e.g. car models):
4.3. Define the key column, this is the field in the input file containing the category. In this example, the key column is the car model.
Also, update the period identifier, this value will be the header of the new period. This can be literal or a link in the process, in this example is a link in the process:
4.4. Update the settings, if required.
5. Save the step
Tips and tricks
In the case when the items in your category can change, select "if new keys found, Grow" (see 4.4 above), this will ensure that new items are added to the historical file.