Data Merging API: Inner, Left, and Union Joins

This workflow creates an API to demonstrate data merging using the Merge node, simulating SQL-like joins (inner, left, union) with sample data (ingredients and band members). Key nodes include Webhook (handles POST requests at /api/merge), Input Validation (sets valid flag), Merge nodes (Ingredients in stock from recipe, Merge recipe, Super Band for inner join, left join, and union), Code nodes (A. Ingredients Needed, B. Ingredients in stock, A. Ingredients, B. Recipe quantities, A. Queen, B. Led Zeppelin), Success Response (returns JSON results), and sticky notes (documentation). No external APIs are used. Customize by updating Code nodes’ data.\n\nSetup Requirements and Configuration: Install n8n from n8n.io for self-hosting or sign up at cloud.n8n.io. No external API credentials are required, as the workflow uses static sample data. Import the JSON workflow in n8n. Configure the Webhook node to use HTTPS and path ‘api/merge’ under Settings > Webhook. Ensure your server supports HTTPS for secure webhook access. For local testing, use a tunneling service like ngrok to make the webhook publicly accessible. Verify internet connectivity for the n8n instance accessibility. No additional services or credentials are needed, making setup straightforward for beginners.\n\nTesting and Deployment Steps: Activate the workflow to get the Webhook URL (e.g., https://your-n8n-instance/api/merge). Test by sending a POST request (body can be empty, as data is static). Success response returns JSON with inner_join (matching ingredients), left_join (ingredients with quantities), and union (combined band members). Check n8n logs for errors like ‘Webhook not accessible’ or ‘Invalid node execution.’ Validate outputs: ensure inner_join contains only matching items (e.g., Eggs, Lemon, Sugar), left_join includes quantities, and union lists all band members. Debug using n8n logs for webhook or execution issues. Ensure stable internet for reliable webhook performance. Customize by editing the Code nodes’ JavaScript to change sample data (e.g., different ingredients or bands).