Query PostgreSQL Database with Natural Language using GPT-4o-mini

This Database SQL Query Agent convert natural language into sql query to get results

Turn your PostgreSQL database into a conversational AI agent! Ask questions in plain English and get instant data results without writing SQL.

✨ What It Does

Natural Language Queries**: "Show laptops under $500 in stock" → Automatic SQL generation Smart Column Mapping**: Understands your terms and maps them to actual database columns Conversational Memory**: Maintains context across multiple questions Universal Compatibility**: Works with any PostgreSQL table structure

🎯 Perfect For

Business analysts querying data without SQL knowledge Customer support finding information quickly Product managers analyzing inventory/sales data Anyone who needs database insights fast

🚀 Quick Setup

Step 1: Prerequisites n8n instance (cloud/self-hosted) PostgreSQL database with read access OpenAI API key/You can use other LLM as well

Step 2: Import & Configure Import this workflow template into n8n Add Credentials: OpenAI API: Add your API key PostgreSQL: Configure database connection Set Table Name: Edit "Set Table Name" node → Replace "table_name" with your actual table Test Connection: Ensure your database user has SELECT permissions

Step 3: Deploy & Use Start the workflow Open the chat interface Ask questions like: "Show all active users" "Find orders from last month over $100" "List products with low inventory"

🔧 Configuration Details

Required Settings Table Name**: Update in "Set Table Name" node Database Schema**: Default is 'public' (modify SQL if different) Result Limit**: Default 50 rows (adjustable in system prompt)

Optional Customizations Multi-table Support**: Modify system prompt and add table selection logic Custom Filters**: Add business rules to restrict data access Output Format**: Customize response formatting in the agent prompt

💡 Example Queries

E-commerce "Show me all electronics under $200 that are in stock"

HR Database "List employees hired in 2024 with salary over 70k"

Customer Data "Find VIP customers from California with recent orders"

🛡️ Security Features

Read-only Operations**: Only SELECT queries allowed SQL Injection Prevention**: Parameterized queries and validation Result Limits**: Prevents overwhelming queries Safe Schema Discovery**: Uses information_schema tables

🔍 How It Works

Schema Discovery: Agent fetches table structure and column info Query Planning: Maps natural language to database columns SQL Generation: Creates safe, optimized queries Result Formatting: Returns clean, user-friendly data

⚡ Quick Troubleshooting

No Results**: Check table name and ensure data exists Permission Error**: Verify database user has SELECT access Connection Failed**: Confirm PostgreSQL credentials and network access Unexpected Results**: Try more specific queries with exact column names

🎨 Use Cases

Inventory Management**: "Show low-stock items by category" Sales Analysis**: "Top 10 products by revenue this quarter" Customer Support**: "Find customer orders with status 'pending'" Data Exploration**: "What are the unique product categories?"

🔧 Advanced Tips

Performance**: Add database indexes on frequently queried columns Customization**: Modify the system prompt for domain-specific terminology Scaling**: Use read replicas for high-query volumes Integration**: Connect to Slack/Teams for team-wide data access

Tags: AI, PostgreSQL, Natural Language, SQL, Business Intelligence, LangChain, Database Query

Difficulty: Beginner to Intermediate
Setup Time: 10-15 minutes