CODEWITHSUNDEEP
dbt
UJIN
UJIN

Reputation: 1758

How to access model metadata from custom materialization

I am currently writing a custom dbt materialization and I would like to know what is the best way / pattern to access the "current" model metadata from the materialization itself.

Background

My model consists of two files:

version: 2

models:
 - name: sample_model
    description: This is a test view to test a materialization
    config:
      schema: temp
      materialized: custom_view
    columns:
      - name: custom_view_column_a
        description: This is a test column A in a view
      - name: custom_view_column_b
        description: This is a test column B in a view

SELECT
  1 AS custom_view_column_a,
  2 AS custom_view_column_b

My solution

In my custom materialization (custom_view) I would like, for example, to access the columns defined in the model metadata (sample_model.yaml). For the moment I could access them using the graph variable, in this way:

{% set models = [] %}
{% for node in graph.nodes.values() | selectattr("resource_type", "equalto", "model") | selectattr("name", "equalto", this.identifier) %}
    {% do models.append(node) %}
{% endfor %}

{% set model_metadata = models|first %}
{% set model_columns = model_metadata.get("columns") %}

Possible improvements

This approach works quite well, however it "feels" a bit like (ab)using a sort of "global variable". Also the graph could become very large considering it stores both the metadata and the SQL of all the models in the project!

Is there any other (local) object / variable I can access from the materialization that only stores the metadata of the model it's currently being materialized?

Upvotes: 1

Views: 1062

Answers (1)

tconbeer
tconbeer

Reputation: 5805

{{ model }} gives you the data from the graph for the current model node. I think it should work inside a materialization:

{% set model_metadata = model %}

You may want to gate it with execute -- I'm not really sure if the first parsing pass templates the materialization code:

{% set model_metadata = model if execute else {} %}

Upvotes: 1

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