How to sum values from relationship children in a NocoBase form?

English Forum Questions
1

Hi all,
I’m using NocoBase v1.9.40 and trying to calculate the SUM of a numeric field from child (one-to-many) relationship records and display it in the parent form.
I’ve tried using workflows, but it only updates after saving the record. I’m looking for a way to:

  • Calculate or update the sum before or without saving
  • Show the result in a read-only or calculated field on the parent form
    Questions:
  • Is real-time summing of relationship children supported in v1.9.40?
  • Are there alternatives using formulas, hooks, or custom components instead of workflows?
    Any guidance would be appreciated.
2

Hello, real-time calculation is not supported, but you can use linked rules to calculate and assign values ​​when the form page is opened.

3

Do you have any articles or specific documentation about this? I’ve spent some time researching it but couldn’t find anything

4

refer to
Linkage Rules - NocoBase