@goodware/mysql

@goodware/mysql: A mysql2-based connection helper

Better documentation is coming

Links

• npm
• git
• API

Requirements

ES 2017

Installation

npm i --save @goodware/mysql

Breaking change! Peer dependencies for versions 3+

All runtime dependencies in version 3 were changed to use peer dependencies.

If you're missing a dependency, you have three options:

1. Stick with version 2.x

npm i --save @goodware/mysql@2

Or, in package.json dependencies:

"@goodware/mysql": "^2.0.0"

1. Add the missing dependencies to your package.json
2. upgrade to npm version 7

npm i -g npm@7

Features

• Creates database connections via mysql2-promise, optionally from a pool, with exponential backoff retry
• Handles AWS RDS passwordless IAM connections
• Manages database transactions by wrapping begin/end around a function invocation

Notes

• mysql2 Connection objects are from mysql2-promise, so their methods execute(), query() etc. return Promises.
• If usePool is true, "await stop()" must be called on the MySqlConnector object if you wish to release the connections in the pool. Letting these objects go out of scope without stopping them will not close the connections.

Usage

1. Create an instance of the class that is exported by this module
2. Call exectue() or transaction(). These accept a function that accepts a mysql2 connection object. The provided functions usually call query() on the connection object.
3. If you're using connection pooling, call stop() to close all connections. This is necessary if:

• The app instantiates multiple instances to access the same database server. It is recommended to use a single global instance to avoid this issue.
• The app hangs when exiting

Logger

The options provided by the constructor and all other methods accept an optional 'logger' function or object. If an object is provided, it must have the method log():

interface Logger {
  /**
   * @param tags Typically includes a logging level name, like info or debug.
   * @param message An object with at least a message property
   */
  log(tags: string[] | string, message: Record<string, unknown>): void;
}

Usage

The following program outputs 'success' to the console.

const mysql = require('@goodware/mysql');
const pack = require('../package.json');

const config = {
  // host: '0.0.0.0', // This is the default
  // port: 3306, // This is the default
  // user: 'root', // This is the default
  // database: 'mysql', // Ths is the default
  password: 'password',
};

const connector = new mysql(config, console.log); // The second parameter is a logger function

async () => {
  const result = await connector.execute( async (connection) => {
    const [results] = await connection.query(`select 'success' AS status`);
    return results[0].status;
  });
  console.log(result);
  await connector.stop();
}().then(console.info, console.error);