Configure database connection

Migrating from forest-express-sequelize

When using the onboarding wizard, you connected to your database using the @forestadmin/datasource-sql connector. To ease the migration, we recommend switching to the @forestadmin/datasource-sequelize connector.

Start by changing the dependency in your agent

$ npm install @forestadmin/datasource-sequelize sequelize

Then you will need to copy your Sequelize models to the new project and change the index file.

const { createAgent } = require('@forestadmin/agent');
const { createSequelizeDataSource } = require('@forestadmin/datasource-sequelize');
const sequelizeInstance = require('./sequelize-instance');

// Create agent and import collections from sequelize
const agent = createAgent(options).addDataSource(createSequelizeDataSource(sequelizeInstance));

Migrating from forest-express-mongoose

Connect to the database

Connecting to a MongoDB instance is very similar: using the mongoose ODM is required. We officially support mongoose >= 6.0, but customers have reported working installations with 5.x.

You will need to:

• Install the @forestadmin/datasource-mongoose package.

• Copy your mongoose models to the new project.

• Create a new mongoose connection to the same database as the old one.

const { createAgent } = require('@forestadmin/agent');
const { createMongooseDataSource } = require('@forestadmin/datasource-mongoose');
const connection = require('./mongoose-connection');

// Create agent and import collections from mongoose.connection
const agent = createAgent(options).addDataSource(createMongooseDataSource(connection));

Replicate your legacy agent flattener configuration

If you are using the forest-express-mongoose agent, you probably are using the flattener ↗ feature.

In the new agent, the flattener is more capable, but the behavior of the new auto mode is different.

To replicate the behavior of the old agent, you will need to use the manual mode and configure the flattener manually.

You may have noticed that a flattenMode: 'legacy' option is available. This option does not replicate the behavior of legacy agents, but the behavior of a previous version of the model flattener in the new agents.

If you are migrating from a legacy agent, use the manual mode.

Before

import { collection } from 'forest-express-mongoose';

collection('users', {
  /** ... other options ... */
  fieldsToFlatten: [
    // Flatten the contactDetails field
    'contactDetails',

    // Flatten the characteristics field, but only the first level
    { field: 'characteristics', level: 1 },
  ],
});

After

If you were using fieldsToFlatten in your old agent.

const agent = createAgent(options).addDataSource(
  createMongooseDataSource(connection, {
    flattenMode: 'manual',
    flattenOptions: {
      users: {
        asFields: [
          // Flatten the contactDetails field
          'contactDetails',

          // Flatten the characteristics field, but only the first level
          { field: 'characteristics', level: 1 },
        ],
      },
    },
  }),
);

Otherwise

const agent = createAgent(options).addDataSource(
  createMongooseDataSource(connection, { flattenMode: 'none' }),
);