Creating Models

How to create a model to query a source.

Modelsare 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 Modelson 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.

# 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 config from the last page, pared down to one data source. You register the users model with the source as follows.

# 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.

preen source validate
preen model build