MCP MySQL Server

Instructions

Implementation Reference

• src/index.ts:415-439 (handler)

  The handler function for the 'list_tables' tool. It ensures a database connection, executes 'SHOW TABLES' query using the MySQL connection pool, logs the operation, and returns the list of tables as a formatted JSON string in the MCP response format.

  private async handleListTables(requestId: string) {
    await this.ensureConnection();
  
    try {
      console.error(`[${requestId}] Executing SHOW TABLES`);
      const [rows] = await this.pool!.query('SHOW TABLES');
      console.error(`[${requestId}] SHOW TABLES completed, found ${Array.isArray(rows) ? rows.length : 0} tables`);
  
      return {
        content: [
          {
            type: 'text',
            text: JSON.stringify(rows, null, 2),
          },
        ],
      };
    } catch (error) {
      const errorMsg = getErrorMessage(error);
      console.error(`[${requestId}] Failed to list tables: ${errorMsg}`);
      throw new McpError(
        ErrorCode.InternalError,
        `Failed to list tables: ${errorMsg}`
      );
    }
  }

• src/index.ts:236-249 (registration)

  Registration of the 'list_tables' tool in the ListToolsRequestSchema handler. Defines the tool name, description, and input schema (with no required parameters).

  {
    name: 'list_tables',
    description: 'List all tables in the database',
    inputSchema: {
      type: 'object',
      properties: {
        random_string: {
          type: 'string',
          description: 'Dummy parameter for no-parameter tools',
        }
      },
      required: [], // 修改为可选参数
    },
  },

• src/index.ts:239-248 (schema)

  Input schema definition for the 'list_tables' tool, specifying an optional dummy parameter since the tool takes no real inputs.

  inputSchema: {
    type: 'object',
    properties: {
      random_string: {
        type: 'string',
        description: 'Dummy parameter for no-parameter tools',
      }
    },
    required: [], // 修改为可选参数
  },