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What are the exact steps to reproduce this issue?
Hi,
I have a table with the following columns:
Date (DD-MM-YYYY)
Month (MM-YYYY)
Payment (€)
I want to calculate the total amount of payments per month.
To do that, I created another table called “Payments_month_2026” containing all months from 01-2026 to 12-2026 (12 rows total).
In this table, I created:
a link to the “Payments” table
a Rollup field
Currently, I have to manually link each payment to the corresponding month, and the Rollup works correctly.
However, I would like to automate this process so that payments are automatically linked based on the month and the sum per month automatically calculated. At the end I want to display the paiements per months in the App Builder.
It depends a little bit on how the records are inserted in the Payments table. Do you insert them manually in the grid view, through a form view or through an interface in the application builder?
Each way requires the use of the datetime_format function. This function can convert the value of your date field to the format MM-YYYY. Since this is also the value of the primary field of your Payments_month_2026 table, you can use that function to set a value for the linked field.
Manually in the grid view
You will need an automation that is triggered when the Date field is updated. Based on the date you can set a value for the link to table field using the formula datetime_format([date_from_previous_node],’MM-YYYY’)
Through a form view
It is the same automation as with the grid view, but you can use the Rows are created trigger.
Through the app builder
You can use an Action that creates a new row and set the value of the linked field through the datetime_format function