> For the complete documentation index, see [llms.txt](https://preen.gitbook.io/preen-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://preen.gitbook.io/preen-docs/getting-started/hello-world/creating-models.md).

# Creating Models

How to create a model to query a source.

[Models](/preen-docs/concepts/models.md)are how you define the data you want to work with from a given data source. Don't think of a Model as your final result or query set, rather its all the relevant data from which you may query your final result set.

Read more about the rationale behind [Models](/preen-docs/concepts/models.md)on its concept page.

## Defining a Model

You can define models in two ways, adding a `models.yaml` file to the `PREEN_CONFIG_PATH` or adding individual model files to the `~/.preen/models` directory. You may save a model file anywhere you'd like, so long as its parent directory is specified by `PREEN_MODELS_PATH`

Here's an example `database` model. **Note that column names need to be fully qualified, i.e. users.id instead of id.**

```yaml
# FILENAME: ~/.preen/models/users.yaml
name: users # This name needs to be unique
type: database
query: |
  select
    users.id,
    users.first_name,
    users.last_name,
    users.birthday
  from
    users;
```

## Registering a Model with a Source

Consider a simplified [https://github.com/hyphasql/hypha/blob/main/docs/concepts/source.md](https://github.com/hyphasql/hypha/blob/main/docs/concepts/source.md "mention") config from the last page, pared down to one data source. You register the users model with the source as follows.

```yaml
# FILENAME: ~/.preen/sources.yaml
sources:
  - name: postgres-model
    engine: postgres
    connection:
      host: localhost
      port: 33061
      database: postgres
      username: root
      password: myp@assword
    models:
      - users
```

You can now validate and build your models in Preen.

```bash
preen source validate
preen model build
```