How do I map Supabase node commands to native Postgres operations in n8n?

Below is an outline of how you might convert your Supabase RAG IA workflow to use native Postgres nodes in n8n:

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1. Understand the Differences in Nodes

• Supabase Node
  • Offers operations specifically tailored to Supabase (like handling rows for create, get, update, delete).
  • Uses a built‐in abstraction for common tasks; some commands might be “hidden” behind the node’s interface.

• Postgres Node
  • Provides a set of operations: Delete, Execute Query, Insert, Insert or Update, Select, and Update.
  • For custom logic (that might have been done automatically in the Supabase node), you can use the Execute Query operation to run raw SQL queries with query parameters.

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2. Migrating the Workflow

If your current Supabase workflow, for example, creates a new row or retrieves data for retrieval-augmented generation (RAG), you can map these tasks to the following Postgres operations:

• Creating rows:
  Use the Insert (or Insert or Update) operation. If you need to insert data coming from an upstream RAG process, map the incoming JSON to the columns.

• Retrieving rows:
  Use the Select operation. If you have a dynamic query (for example, building an IN clause with multiple parameters), you can do so using the Execute Query operation with expressions to generate the placeholders dynamically. (See the documentation on using query parameters in the Postgres node for details.)

• Updating or deleting rows:
  Use the Update or Delete operations accordingly. If the logic is more complex, again switch to a custom SQL query via Execute Query.

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3. Sample Workflow Steps

Below is a simplified example of how you might structure such a workflow:

1. Credential Setup
   • Configure your Postgres credentials in n8n (using the Postgres credential configuration from the docs).
   • Note: In your setup you’re running n8n via Docker on Unraid with Postgres 16—ensure your environment variables and host settings match your setup.

2. Data Retrieval
   • Add a Postgres node with the Select operation to retrieve the rows needed for your RAG step.
   • Example – selecting rows with custom conditions:

   SQLCopied
   SELECT * FROM my_table WHERE category IN ({{ $json.categories.map((c, index) => "$" + (index + 1)).join(', ') }});

   • Supply your array of categories via Query Parameters.

3. Data Insertion/Update
   • Use the Insert or Update node operation (depending on your logic) to store new RAG results.
   • Map the fields from your RAG generation process to the column names.

4. Custom SQL Commands
   • If the Supabase node was handling certain custom commands automatically (for example, handling complex row-level security or inserts), replicate that using the Execute Query node.
   • This lets you write a full SQL command with prepared statement placeholders and appropriate parameters.

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4. Additional Note on n8n EXECUTIONS_PROCESS

You asked how to see the n8n EXECUTIONS_PROCESS setting. Since you’re running via Docker, you can check:

• The environment variables provided to your container (e.g., via your Docker Compose file).

• You can log into your running container and print out environment variables using a command such as:

  BASHCopied
  docker exec -it <container_id> env | grep EXECUTIONS_PROCESS

Adjust your Docker configuration if you need to change the behavior (default is usually set to “own” or “main”).

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Final Thoughts

When migrating from the Supabase node to the Postgres node:

• Map operations: Each Supabase command generally has an equivalent in Postgres.
• Rewrite custom logic: Use the Execute Query node for any SQL that isn’t covered by the default operations.
• Use query parameters for secure, dynamic queries.

By replacing Supabase-specific operations with the native Postgres operations and writing custom queries where needed, you can recreate your RAG IA workflow with Postgres in n8n.

Hope this helps clarify the workflow transition!