Jansen003

Posted on May 28

I Built a Python MCP Server for Databases — So Claude Can Query My DB Directly

#database #mcp #python #showdev

I got tired of switching between Claude Code and my database client every time I needed to check some data. So I built mcp-database — a Python MCP server that lets Claude query SQLite, PostgreSQL, and MySQL databases directly.

The Problem

You are in Claude Code, writing a feature. You need to check what columns the orders table has. What do you do?

Open a new terminal
Connect to the database
Run DESCRIBE orders
Copy the result
Go back to Claude
Paste it

Six steps for a simple question. Every time.

The Solution

With mcp-database, you just ask Claude:

"What columns does the orders table have?"

Claude calls the get_table_info tool and answers directly. No context switching.

Quick Start

pip install mcp-database
claude mcp add mcp-database -e MCP_DATABASE_URL=sqlite:///your.db -- mcp-database

That is it. Now you can ask Claude things like:

"What tables are in my database?"
"Show me the schema for the users table"
"Query the top 10 orders by amount"
"Find all columns related to email"
"Sample some rows from the products table"

8 Tools

Tool	What It Does
`list_databases`	List all configured database connections
`list_tables`	List all tables
`get_table_info`	Table details (columns, types, row count)
`get_schema`	Full CREATE TABLE statements
`query`	Execute read-only SQL
`execute`	Write operations (opt-in only)
`sample_rows`	See what the data looks like
`search_tables`	Search tables/columns by keyword

Multi-Database Support

# SQLite (built-in)
MCP_DATABASE_URL=sqlite:///path/to/db.sqlite

# PostgreSQL
pip install "mcp-database[postgres]"
MCP_DATABASE_URL=postgres://user:pass@localhost:5432/mydb

# MySQL
pip install "mcp-database[mysql]"
MCP_DATABASE_URL=mysql://user:pass@localhost:3306/mydb

Security First

Read-only by default — your data is safe
Write opt-in — must explicitly set MCP_DATABASE_READ_ONLY=false
Statement detection — write tool rejects SELECT statements
Row limits — max 100 rows by default, configurable

Why Python?

Largest developer community — lower contribution barrier
Uses the official mcp SDK (FastMCP) — not reinventing the wheel
Minimal dependencies — fast install

Claude Desktop Support

Works with Claude Desktop too:

{
  "mcpServers": {
    "database": {
      "command": "mcp-database",
      "env": {
        "MCP_DATABASE_URL": "sqlite:///your.db"
      }
    }
  }
}

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