Connect.md

Connect

Once you have defined a data model, you need to create connections in order to communicate with a database server.

Usage

import mysql from 'maeva-mysql';
const connection = data.connect(mysql());

Connector

You need a connector to establish a connection. View Connectors guide. You can also [write your own connector](Write your own connector.md).

Connection consumption by queries

This is a classic way to connect to a database server and send it queries:

import mysql from 'maeva-mysql';
data.connect(mysql());
await data.findMany(dataModel, 100);

When you create a new connection, it gets cached as an available connection. All the connection requesters (find*, update*, etc) gets assigned a random connection in pool. Here, findMany will get executed once mysql link is established.

Database

Each connection should have a database name.

Events

## connected

Fired when connection is successfully connected to database server.

const connection = data.connect(connector);
data.connected(connection, () => console.log('Connection established'));

## disconnected

Fired when connection gets disconnected from database server.

const connection = data.connect(connector);
data.disconnected(connection, () => console.log('Connection end'));

## inserted

Fired when a new document is added in database (provided insertion was made via maeva).

const connection = data.connect(connector);
data.inserted(connection, (collection, document) => console.log({inserted: {collection, document}}));

## removed

Fired when a document is removed from database (provided removal was made via maeva).

const connection = data.connect(connector);
data.updated(connection, (collection, document) => console.log({updated: {collection, document}}));

## updated

Fired when a document is updated from database (provided update was made via maeva).

const connection = data.connect(connector);
data.updated(connection, (collection, document) => console.log({updated: {collection, document}}));

Multiple connections

Reconnect

Disconnect