> ## Documentation Index > Fetch the complete documentation index at: https://docs.forest.app/llms.txt > Use this file to discover all available pages before exploring further. # Add many existing records at the same time (hasMany-belongsTo relationship) > This example shows how to associate multiple existing records at once to a record using a simple smart action. ### Requirements * An admin backend running on `forest-express-sequelize` * Relationship **One-To-Many** between two collections (in this example an organization **hasMany** companies \<-> a company **belongsTo** an organization) ## How it works ### Directory: **/forest** Create a new smart action in the forest file of the collection with the **hasMany relationship** (organizations in this example). This smart action will be usable on a single record (`type: 'single'`). We will create two fields in the smart action form, one will be used for the **search** on the referenced collection and the second will be used to see the **selection** made by the operator. ### **Directory: /routes** When the user validates the action, this route is called. We will use the **selection** to retrieve all companies' ids and then updates all companies `organizationId` field to create the associations.\ \ *In addition, once the smart action has been successfully run, it refreshes the relationship to properly display newly added associations.*