Meadow Connection MySQL

A MySQL connection pool provider for the Meadow ORM. Wraps mysql2 as a Fable service, providing connection pooling with named placeholders, auto-connect support, and DDL generation from Meadow table schemas.

Features

• MySQL2 Connection Pooling -- High-performance pooled connections via mysql2
• Fable Service Provider -- Registers with a Fable instance for dependency injection, logging, and configuration
• Named Placeholders -- Automatically enables named placeholders for parameterized queries
• Auto-Connect -- Optional automatic connection on instantiation via the MeadowConnectionMySQLAutoConnect flag
• Schema-Driven DDL -- Generates CREATE TABLE IF NOT EXISTS statements from Meadow table schemas with primary keys, UTF-8 charset, and proper column types
• Connection Safety -- Guards against creating duplicate connection pools with descriptive logging (passwords are never leaked)
• Settings Coercion -- Accepts both Meadow-style (Server, Port, User) and mysql2-native (host, port, user) configuration formats

Installation

npm install meadow-connection-mysql

Quick Start

const libFable = require('fable');
const MeadowConnectionMySQL = require('meadow-connection-mysql');

let fable = new libFable(
{
	MySQL:
	{
		Server: '127.0.0.1',
		Port: 3306,
		User: 'root',
		Password: 'PASSWORD',
		Database: 'my_app',
		ConnectionPoolLimit: 20
	},
	MeadowConnectionMySQLAutoConnect: true
});

fable.serviceManager.addAndInstantiateServiceType('MeadowMySQLProvider',
	MeadowConnectionMySQL);

// Query using the connection pool
fable.MeadowMySQLProvider.pool.query('SELECT * FROM Book LIMIT 10',
	(pError, pRows, pFields) =>
	{
		console.log(`Found ${pRows.length} books.`);
	});

Configuration

The MySQL connection settings can be provided through Fable settings or the service provider options.

Via Fable Settings

let fable = new libFable(
{
	MySQL:
	{
		Server: '127.0.0.1',
		Port: 3306,
		User: 'root',
		Password: 'PASSWORD',
		Database: 'my_app',
		ConnectionPoolLimit: 20
	}
});

Via Provider Options

let connection = fable.instantiateServiceProvider('MeadowConnectionMySQL',
{
	MySQL:
	{
		host: '127.0.0.1',
		port: 3306,
		user: 'root',
		password: 'PASSWORD',
		database: 'my_app',
		connectionLimit: 20
	}
}, MeadowConnectionMySQL);

Both Meadow-style property names (Server, Port, User, Password, Database, ConnectionPoolLimit) and mysql2-native names (host, port, user, password, database, connectionLimit) are supported. The provider automatically coerces the Meadow format to the mysql2 format.

Auto-Connect

Set MeadowConnectionMySQLAutoConnect to true in either Fable settings or provider options to connect automatically on instantiation:

let fable = new libFable(
{
	MySQL: { /* ... */ },
	MeadowConnectionMySQLAutoConnect: true
});

API

connect()

Create the MySQL connection pool synchronously. Guards against double-connect — calling connect() on an already-connected instance logs an error and skips pool creation.

connectAsync(fCallback)

Async wrapper around connect() for consistency with other Meadow connection providers.

| Parameter | Type | Description | |-----------|------|-------------| | fCallback | Function | Callback receiving (error, connectionPool) |

pool (getter)

Returns the underlying mysql2 connection pool for direct query access.

connected (property)

Boolean indicating whether the connection pool has been created.

generateCreateTableStatement(pMeadowTableSchema)

Generate a CREATE TABLE IF NOT EXISTS SQL statement from a Meadow table schema object. Tables are created with utf8mb4 charset and utf8mb4_unicode_ci collation.

| Parameter | Type | Description | |-----------|------|-------------| | pMeadowTableSchema | Object | Meadow table schema with TableName and Columns array |

createTable(pMeadowTableSchema, fCallback)

Execute a CREATE TABLE statement against the connected database.

createTables(pMeadowSchema, fCallback)

Create all tables defined in a Meadow schema object (iterates pMeadowSchema.Tables sequentially).

generateDropTableStatement(pTableName)

Generate a DROP TABLE IF EXISTS SQL statement for the given table name.

Column Type Mapping

| Meadow Type | MySQL Column | |-------------|--------------| | ID | INT UNSIGNED NOT NULL AUTO_INCREMENT (with PRIMARY KEY) | | GUID | CHAR(size) with default GUID (size defaults to 36) | | ForeignKey | INT UNSIGNED NOT NULL DEFAULT '0' | | Numeric | INT NOT NULL DEFAULT '0' | | Decimal | DECIMAL(size) | | String | CHAR(size) NOT NULL DEFAULT '' | | Text | TEXT | | DateTime | DATETIME | | Boolean | TINYINT NOT NULL DEFAULT '0' |

Part of the Retold Framework

Meadow Connection MySQL is a database connector for the Meadow data access layer:

• meadow -- ORM and data access framework
• foxhound -- Query DSL used by Meadow
• stricture -- Schema definition tool
• meadow-endpoints -- RESTful endpoint generation
• meadow-connection-mssql -- MSSQL connector
• meadow-connection-sqlite -- SQLite connector
• fable -- Application services framework

Testing

Run the test suite:

npm test

Run with coverage:

npm run coverage

Related Packages

• meadow -- Data access and ORM
• meadow-connection-rocksdb -- RocksDB connection provider
• fable -- Application services framework

License

MIT

Contributing

Pull requests are welcome. For details on our code of conduct, contribution process, and testing requirements, see the Retold Contributing Guide.