# Migration guide from alpha.12.1 to alpha.12.2

Here are the major changes:

Update relation management
Fix many bugs and enhancement

Usefull links:

💡 TIP

Feel free to join us on Slack (opens new window) and ask questions about the migration process.

# Getting started

Install Strapi alpha.12.2 globally on your computer. To do so run npm install strapi@3.0.0-alpha.12.2 -g.

When it's done, generate a new empty project strapi new myNewProject (don't pay attention to the database configuration).

# Update node modules

Update the Strapi's dependencies version (move Strapi's dependencies to 3.0.0-alpha.12.2 version) of your project.

Run npm install strapi@3.0.0-alpha.12.2 --save to update your strapi version and then run the same command for strapi-mongoose or strapi-bookshelf depending of the module you use in your application.

# Update the Admin

💡 TIP

If you did custom update of the admin, you will have to manually migrate your update.

Delete your old admin folder and replace it by the new one.

# Update the Plugins

💡 TIP

If you did custom update on one of the plugin, you will have to manually migrate your update.

Copy the fields and relations you had in your /plugins/users-permissions/models/User.settings.json and /plugins/users-permissions/config/jwt.json file in the new one.

Then, delete your old plugins folder and replace it by the new one.

# ⚠️ Update API services

You will have to update services of you generated API.

Replace Article by your Content Type name in each functions.

For add function:

add: async (values) => {
  // Extract values related to relational data.
  const relations = _.pick(values, Article.associations.map(ast => ast.alias));
  const data = _.omit(values, Article.associations.map(ast => ast.alias));

  // Create entry with no-relational data.
  const entry = await Article.create(data);

  // Create relational data and return the entry.
  return Article.updateRelations({ id: entry.id, values: relations });
},

For edit function:

edit: async (params, values) => {
  // Extract values related to relational data.
  const relations = _.pick(values, Article.associations.map(a => a.alias));
  const data = _.omit(values, Article.associations.map(a => a.alias));

  // Update entry with no-relational data.
  const entry = await Article.update(params, data, { multi: true });

  // Update relational data and return the entry.
  return Article.updateRelations(Object.assign(params, { values: relations }));
},

For remove function:

remove: async params => {
  // Select field to populate.
  const populate = Article.associations
    .filter(ast => ast.autoPopulate !== false)
    .map(ast => ast.alias)
    .join(' ');

  // Note: To get the full response of Mongo, use the `remove()` method
  // or add spent the parameter `{ passRawResult: true }` as second argument.
  const data = await Article.findOneAndRemove(params, {}).populate(populate);

  if (!data) {
    return data;
  }

  await Promise.all(
    Article.associations.map(async association => {
      const search =
        _.endsWith(association.nature, 'One') || association.nature === 'oneToMany'
          ? { [association.via]: data._id }
          : { [association.via]: { $in: [data._id] } };
      const update =
        _.endsWith(association.nature, 'One') || association.nature === 'oneToMany'
          ? { [association.via]: null }
          : { $pull: { [association.via]: data._id } };

      // Retrieve model.
      const model = association.plugin
        ? strapi.plugins[association.plugin].models[association.model || association.collection]
        : strapi.models[association.model || association.collection];

      return model.update(search, update, { multi: true });
    })
  );

  return data;
};

That's all, you have now upgraded to Strapi alpha.12.2.