Add MySQL support to MCP Database Server

Updated package.json and package-lock.json to include MySQL dependencies. Enhanced README with MySQL usage instructions and configuration details. Modified index.ts to handle MySQL connection parameters and logging. Added MysqlAdapter for database interactions.

src/db/mysql-adapter.ts

@@ -0,0 +1,135 @@
+import { DbAdapter } from "./adapter.js";
+import mysql from "mysql2/promise";
+
+/**
+ * MySQL database adapter implementation
+ */
+export class MysqlAdapter implements DbAdapter {
+  private connection: mysql.Connection | null = null;
+  private config: mysql.ConnectionOptions;
+  private host: string;
+  private database: string;
+
+  constructor(connectionInfo: {
+    host: string;
+    database: string;
+    user?: string;
+    password?: string;
+    port?: number;
+    ssl?: boolean | object;
+    connectionTimeout?: number;
+  }) {
+    this.host = connectionInfo.host;
+    this.database = connectionInfo.database;
+    this.config = {
+      host: connectionInfo.host,
+      database: connectionInfo.database,
+      port: connectionInfo.port || 3306,
+      user: connectionInfo.user,
+      password: connectionInfo.password,
+      connectTimeout: connectionInfo.connectionTimeout || 30000,
+      multipleStatements: true,
+    };
+    if (typeof connectionInfo.ssl === 'object' || typeof connectionInfo.ssl === 'string') {
+      this.config.ssl = connectionInfo.ssl;
+    } else if (connectionInfo.ssl === true) {
+      this.config.ssl = {};
+    }
+  }
+
+  /**
+   * Initialize MySQL connection
+   */
+  async init(): Promise<void> {
+    try {
+      console.error(`[INFO] Connecting to MySQL: ${this.host}, Database: ${this.database}`);
+      this.connection = await mysql.createConnection(this.config);
+      console.error(`[INFO] MySQL connection established successfully`);
+    } catch (err) {
+      console.error(`[ERROR] MySQL connection error: ${(err as Error).message}`);
+      throw new Error(`Failed to connect to MySQL: ${(err as Error).message}`);
+    }
+  }
+
+  /**
+   * Execute a SQL query and get all results
+   */
+  async all(query: string, params: any[] = []): Promise<any[]> {
+    if (!this.connection) {
+      throw new Error("Database not initialized");
+    }
+    try {
+      const [rows] = await this.connection.execute(query, params);
+      return Array.isArray(rows) ? rows : [];
+    } catch (err) {
+      throw new Error(`MySQL query error: ${(err as Error).message}`);
+    }
+  }
+
+  /**
+   * Execute a SQL query that modifies data
+   */
+  async run(query: string, params: any[] = []): Promise<{ changes: number, lastID: number }> {
+    if (!this.connection) {
+      throw new Error("Database not initialized");
+    }
+    try {
+      const [result]: any = await this.connection.execute(query, params);
+      const changes = result.affectedRows || 0;
+      const lastID = result.insertId || 0;
+      return { changes, lastID };
+    } catch (err) {
+      throw new Error(`MySQL query error: ${(err as Error).message}`);
+    }
+  }
+
+  /**
+   * Execute multiple SQL statements
+   */
+  async exec(query: string): Promise<void> {
+    if (!this.connection) {
+      throw new Error("Database not initialized");
+    }
+    try {
+      await this.connection.query(query);
+    } catch (err) {
+      throw new Error(`MySQL batch error: ${(err as Error).message}`);
+    }
+  }
+
+  /**
+   * Close the database connection
+   */
+  async close(): Promise<void> {
+    if (this.connection) {
+      await this.connection.end();
+      this.connection = null;
+    }
+  }
+
+  /**
+   * Get database metadata
+   */
+  getMetadata(): { name: string; type: string; server: string; database: string } {
+    return {
+      name: "MySQL",
+      type: "mysql",
+      server: this.host,
+      database: this.database,
+    };
+  }
+
+  /**
+   * Get database-specific query for listing tables
+   */
+  getListTablesQuery(): string {
+    return "SHOW TABLES";
+  }
+
+  /**
+   * Get database-specific query for describing a table
+   */
+  getDescribeTableQuery(tableName: string): string {
+    return `DESCRIBE \`${tableName}\``;
+  }
+}