Loopback relations: querying relations with/without include

loopback-query-relations.js

/* Previously defined in customer-user.json:

"relations": {
    "roles": {
      "type": "hasMany",
      "model": "Role",
      "foreignKey": "principalId",
      "through": "RoleMapping"
    }
  },

*/

let user = await CustomerUser.findById(userId);

logger.debug(user.roles);
// object with querying functions that return a promise: find, create, count, findAll, etc

logger.debug(user.roles());
// undefined

logger.debug(await user.roles.find());
// promise that resolves to all roles associated with user

// Now, same queries, but this time including roles
let user = await CustomerUser.findById(userId, {
  include: 'roles'
});

logger.debug(user.roles);
// object with querying functions that return a promise: find, create, count, findAll, etc

logger.debug(user.roles());
// roles associated with user

logger.debug(await user.roles.find());
// promise that resolves to all roles associated with user