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uniqBy vs. groupBy: What's the Difference?

Doc Auto Team
Doc Auto Team
  • Updated
The core difference between these two functions comes down to data retention. uniqBy removes duplicate records (keeping only the first instance it finds), whereas groupBy reorganizes records that share a common variable into a nested {group} sub-collection so no data is lost.
Here is how they compare using an officer holding two titles (Leslie Knope: President and Secretary):
1. The uniqBy Approach (Data Loss)
  • Syntax: {#affiliations | filter:'role':'Officer' | uniqBy:'participant_profileID'}
  • Result: Leslie Knope is a President.
  • The Catch: The engine stops at the first match, meaning her "Secretary" title is completely dropped from the document.
  • Pro Tip: Always place uniqBy after your standard filters (like status or role) in your function stack so the engine evaluates the correct pool of data before deleting duplicates.
2. The groupBy Approach (Data Retention)
  • Syntax: {#affiliations | filter:'role':'Officer' | groupBy:'participant_profileID'}
  • Result: Leslie Knope is a President and Secretary.
  • How it works: This creates a {group} sub-collection holding both rows of data. Inside the loop, you can use {group | grab:1:'participant_fullName'} to print her name exactly once, and {group | toSentence:'title'} to list all of her combined titles perfectly.