drop_pre_defer.sql

-- dbt run-operation drop_pre_defer --args '{tables_to_drop: [inc_orders,dim_customers]}'

{% macro drop_pre_defer(models_to_drop) %}
    {% if execute %}
        {% for model_to_drop in models_to_drop %} 
            {%- for model in graph.nodes.values() | selectattr("name", "equalto", model_to_drop) -%}
                {% set query %}
                    drop {{model.config.materialized}} if exists {{target.database}}.{{target.schema}}.{{model_to_drop}};
                {% endset %}
                {% do run_query(query) %}
                {{ dbt_utils.log_info("Drop materialized model succesfully: " ~ model_to_drop) }}
            {% endfor %}

        {% endfor %}
    {% endif %}
{% endmacro %}

-- Aux macro to automatically select all inmediate parents of the model 
-- we want to run deferring to prod (model_to_run)
{% macro select_drop_pre_defer(model_to_run) %}
    {% set models_to_drop = [] %} 
    {%- for model in graph.nodes.values() | selectattr("name", "equalto", model_to_run) -%}
        {{ dbt_utils.log_info("Found selected model " ~ model.name ~ ", will look for refs") }}

        {%- for model_ref in model.refs -%}
            {{ dbt_utils.log_info("Found model ref: " ~ model_ref.name) }}
            {{ models_to_drop.append(model_ref.name) }}
        {%- endfor -%}
    {%- endfor -%}

    {{ return(models_to_drop) }}

{% endmacro %}

-- dbt run-operation automate_drop_pre_defer --args '{model_to_run: dim_customers}'
-- Macro that from the model we want to run, deferring to prod, will search 
-- for all immediate parents and will drop those views/tables

{% macro automate_drop_pre_defer(model_to_run) %}
    {% if execute %}
        {% set models_to_drop = select_drop_pre_defer(model_to_run) %} 
        
        {{ dbt_utils.log_info("Found parent models to drop: " ~ models_to_drop) }}
        {{ drop_pre_defer(models_to_drop) }}

    {% endif %}
{% endmacro %}