# Update your models' definition

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## Update your models' definition

Your database schema will evolve over time. Any changes can (and probably should) be applied to your admin backend's models.

{% hint style="info" %}
To upgrade your models definition in your code you need to be at least in the V7 version of `forest-express-sequelize` or `forest-express-mongoose` package. If this is not the case please follow our [migration note](/documentation/extra-help/maintain/upgrade-notes-sql-mongodb/upgrade-to-v7.md).
{% endhint %}

Now you can use the `forest schema:update` command to achieve your goal.

This command is able to create all the missing file for a newly added table in your database. However it will not automatically modify existing files. So if you just added a new field inside an existing table, please just remove the corresponding model file inside your models folder and run the command.

#### Examples

In the following example, we added a new table `customers` on an existing project. This is the output of the `forest schema:update` command.

```
$ forest schema:update
✓ Connecting to your database(s)
✓ Analyzing the database(s)
  create forest/customers.js
  skip forest/staffs.js - already exist.
  skip forest/stores.js - already exist.
  create models/customers.js
  skip models/staffs.js - already exist.
  skip models/stores.js - already exist.
  create routes/customers.js
  skip routes/staffs.js - already exist.
  skip routes/stores.js - already exist.
✓ Generating your files
```

In the next example we just removed a field from the previous added table. After removing the model file from the models folder. This is the output of the `forest schema:update` command.

```
$ forest schema:update
✓ Connecting to your database(s)
✓ Analyzing the database(s)
  skip forest/customers.js - already exist.
  skip forest/staffs.js - already exist.
  skip forest/stores.js - already exist.
  create models/customers.js
  skip models/staffs.js - already exist.
  skip models/stores.js - already exist.
  skip routes/customers.js - already exist.
  skip routes/staffs.js - already exist.
  skip routes/stores.js - already exist.
✓ Generating your files
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.forestadmin.com/documentation/extra-help/maintain/update-your-models-definition.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.