About config variable

The config variable exists to handle end-user configuration for custom materializations. Configs like unique_key can be implemented using the config variable in your own materializations.

For example, code in the incremental materialization like this:

{% materialization incremental, default -%}
  {%- set unique_key = config.get('unique_key') -%}
  ...

is responsible for handling model code that looks like this:

{{
  config(
    materialized='incremental',
    unique_key='id'
  )
}}

Review Model configurations for examples and more information on valid arguments.

config.get

Args:

• name: The name of the configuration variable (required)
• default: The default value to use if this configuration is not provided (optional)

The config.get function is used to get configurations for a model from the end-user. Configs defined in this way are optional, and a default value can be provided.

There are 3 cases:

1. The configuration variable exists, it is not None
2. The configuration variable exists, it is None
3. The configuration variable does not exist

Example usage:

{% materialization incremental, default -%}
  -- Example w/ no default. unique_key will be None if the user does not provide this configuration
  {%- set unique_key = config.get('unique_key') -%}

  -- Example w/ alternate value. Use alternative of 'id' if 'unique_key' config is provided, but it is None
  {%- set unique_key = config.get('unique_key') or 'id' -%}

  -- Example w/ default value. Default to 'id' if the 'unique_key' config does not exist
  {%- set unique_key = config.get('unique_key', default='id') -%}
  ...

config.require

Args:

• name: The name of the configuration variable (required)

The config.require function is used to get configurations for a model from the end-user. Configs defined using this function are required, and failure to provide them will result in a compilation error.

Example usage:

{% materialization incremental, default -%}
  {%- set unique_key = config.require('unique_key') -%}
  ...