Module 4 Lesson 5: Sorting & Filtering

If you pull 1,000 customers from a database, but you only want to email the ones who spent > $500, you need Filtering. If you want to email the "Most Recent" customers first, you need Sorting.

1. The Filter Node

Think of this as a "Sieve."

• Only pass items where price > 100.
• Only pass items where category = 'VIP'.
• Result: The node outputs a smaller list of items, saving you "API Calls" and "CI Minutes" in the following nodes.

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2. The Sort Node

Decide the order of the items.

• Sort by created_at (Descending) to get the newest items.
• Sort by name (Alphabetical).
• Scenario: You want to notify Slack about the 3 Highest Sales of the day. You Sort by value (Desc) and then go to Step 3.

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Visualizing the Process

graph TD
    Start[Input] --> Process[Processing]
    Process --> Decision{Check}
    Decision -->|Success| End[Complete]
    Decision -->|Retry| Process

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3. The Limit Node (The "Cutter")

Only take the first X items.

• "Give me the top 5 results."
• "Skip the first 10 items (Offset) and give me the next 10."
• This is essential for Pagination (reading massive lists in small chunks).

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4. The "No Data" Case

What happens if the Filter node removes EVERYTHING?

• n8n will stop the workflow (by default).
• You can change this behavior in the "Settings" of the node if you want the workflow to continue even with 0 items.

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Exercise: The Curator's Task

1. Create a mock list of 5 items with score from 1 to 100.
2. Filter the list to only include items where score > 50.
3. Sort the remaining items from Highest to Lowest score.
4. Limit the result to only the Top 1 item.
5. Why should you filter as EARLIER as possible in a workflow? (Hint: Cost and Speed).
6. Research: What is the "Remove Duplicates" node?

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Summary

You have completed Module 4: Working with Data. You now know how to read JSON, manipulate strings, calculate math, handle time, and curate your datasets. You have the "DNA" of an automation expert.

Next Module: Advanced Logic: Module 5: Advanced Logical Flow (IF, Switch, Merge).