database-js MySQL2 Adapter

Common errors

• Error: Cannot find module 'database-js'

  cause The `database-js` core package is not installed, but `database-js-mysql2` expects it when used as a driver.
  fix Install the `database-js` package: `npm install database-js`.

• TypeError: Cannot read properties of undefined (reading 'Connection')

  cause Attempting to destructure `Connection` from `require('database-js')` when `database-js` might not be correctly installed or resolved, or `Connection` is not a named export in an unexpected scenario.
  fix Verify `npm list database-js` shows the package, and ensure the import is `const Database = require('database-js').Connection;` if you are using the older `database-js` pattern.

• Error: ER_ACCESS_DENIED_ERROR: Access denied for user 'user'@'host' (using password: YES/NO)

  cause Incorrect MySQL username, password, or host settings in the connection string. The database server rejected the authentication attempt.
  fix Double-check your `DB_USER`, `DB_PASSWORD`, `DB_HOST`, and `DB_PORT` environment variables or hardcoded values. Ensure the user has correct privileges for the specified database.

Warnings

• breaking This project appears to be abandoned, with the last commit in 2018. It is unlikely to receive updates for new Node.js versions, security patches, or compatibility with newer `mysql2` releases, posing potential stability and security risks.
  Fix: Consider migrating to a actively maintained `database-js` driver if available, or a direct `mysql2` client for more current support.
• gotcha The package exclusively uses CommonJS `require()` syntax. It does not natively support ES Modules (`import/export`) and attempting to use them will result in syntax errors or module resolution failures.
  Fix: Ensure your project or file uses CommonJS `require()` statements for importing `database-js-mysql2` and `database-js`.
• gotcha SSL certificate files (ca, key, cert) specified in the connection string are read synchronously using `fs.readFileSync`. In high-performance or serverless environments, this synchronous I/O can block the Node.js event loop, potentially impacting application responsiveness during connection setup.
  Fix: Be aware of the synchronous file access. For critical applications, pre-loading certificates or using an alternative driver that supports asynchronous certificate loading might be preferable if this becomes a performance bottleneck.

Install

• npm install database-js-mysql2 npm
• yarn add database-js-mysql2 yarn
• pnpm add database-js-mysql2 pnpm

Imports

• mysql
  wrong:

  import mysql from 'database-js-mysql2';

  correct:

  const mysql = require('database-js-mysql2');

  The package primarily targets CommonJS environments. ESM imports are not directly supported.
• Connection
  wrong:

  import { Connection } from 'database-js';

  correct:

  const { Connection } = require('database-js');

  When used with `database-js`, the Connection class is imported from the parent `database-js` package, which also targets CommonJS.
• Database
  wrong:

  import Database from 'database-js/Connection';

  correct:

  const Database = require('database-js').Connection;

  Common aliasing pattern for the `database-js` Connection class in CommonJS.

Quickstart

Demonstrates connecting to MySQL using `database-js` with the `database-js-mysql2` driver, including parameterized queries and SSL configuration via connection string. Uses environment variables for credentials.

const Database = require('database-js').Connection;
const fs = require('fs');

// Dummy 'fs' for example to make it runnable without actual files
// In a real scenario, these files would exist on disk.
const caCertPath = './path/to/ca.pem';
const keyPath = './path/to/key.pem';
const certPath = './path/to/cert.pem';

// Mock fs.existsSync and fs.readFileSync for demonstration purposes
const originalExistsSync = fs.existsSync;
const originalReadFileSync = fs.readFileSync;
fs.existsSync = (path) => path === caCertPath || path === keyPath || path === certPath;
fs.readFileSync = (path) => Buffer.from(`mock_certificate_for_${path}`);

(async () => {
    let connection, statement, rows;
    const dbUser = process.env.DB_USER ?? 'my_secret_username';
    const dbPass = process.env.DB_PASSWORD ?? 'my_secret_password';
    const dbHost = process.env.DB_HOST ?? 'localhost';
    const dbPort = process.env.DB_PORT ?? 3306;
    const dbName = process.env.DB_NAME ?? 'my_top_secret_database';

    // Example connection string with SSL parameters, ensuring paths are URL-encoded
    // In a real application, ensure your SSL files are correctly placed and permissions set.
    const connectionString = `mysql2://${dbUser}:${dbPass}@${dbHost}:${dbPort}/${dbName}?ssl[ca]=${encodeURIComponent(caCertPath)}&ssl[key]=${encodeURIComponent(keyPath)}&ssl[cert]=${encodeURIComponent(certPath)}`;

    try {
        connection = new Database(connectionString);
        statement = await connection.prepareStatement("SELECT ? AS user_name_col, ? AS value_col");
        rows = await statement.query('not_so_secret_user', 123);
        console.log('Query Result:', rows);
    } catch (error) {
        console.error('Database Error:', error);
    } finally {
        if (connection) {
            await connection.close();
        }
    }
})();

// Restore original fs methods if necessary in a larger application context
fs.existsSync = originalExistsSync;
fs.readFileSync = originalReadFileSync;