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A post_save signal handler is not updating a related model as expected. What is a common mistake causing this?

medium📝 Debug Q7 of 15
Django - Signals
A post_save signal handler is not updating a related model as expected. What is a common mistake causing this?
AConnecting the signal to the wrong model
BUsing <code>pre_save</code> instead of <code>post_save</code>
CNot calling <code>save()</code> on the related model after updating
DForgetting to import the related model
Step-by-Step Solution
Solution:

  1. Step 1: Understand model update in signals

    Updating a related model requires calling save() to persist changes.

  2. Step 2: Identify common error

    Forgetting to call save() means changes are not saved, causing unexpected behavior.

  3. Final Answer:

    Not calling save() on the related model after updating -> Option C

  4. Quick Check:

    Update related model then call save() [OK]
Quick Trick: Always call save() after modifying related models [OK]
Common Mistakes:
MISTAKES
  • Assuming update auto-saves without save()
  • Confusing signal types with update issues
  • Connecting signal to wrong model but expecting update

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