MCP Server with Database Integration Template

**MCP Server with SQLite/PostgreSQL Integration**

A common pattern: expose your database as MCP tools so Claude or other agents can query and update it.

```typescript // Key pattern: Use parameterized queries to prevent SQL injection server.tool( "query_data", "Search records by field and value", { table: z.enum(["users", "orders", "products"]), field: z.string().describe("Column name to filter by"), value: z.string().describe("Value to match"), limit: z.number().default(10), }, async ({ table, field, value, limit }) => { // NEVER interpolate user input into SQL const rows = await db.query( `SELECT * FROM ${table} WHERE ${field} = $1 LIMIT $2`, [value, limit] ); return { content: [{ type: "text", text: JSON.stringify(rows) }] }; } ); ```

**Security checklist:** - Enum for table names (prevents arbitrary table access) - Parameterized queries (prevents SQL injection) - Row limit (prevents full table dumps) - Read-only by default (add write tools separately with confirmation)