# Rendering Macro within Macro

**URL:** <https://discourse.getdbt.com/t/rendering-macro-within-macro/20001>\
**Category:** Help\
**Tags:** macro, macros\
**Created:** [July 31, 2025, 12:41pm UTC](https://discourse.getdbt.com/t/rendering-macro-within-macro/20001 "2025-07-31T12:41:30Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Priest](https://avatars.discourse-cdn.com/v4/letter/p/9de0a6/32.png) [@Priest](https://discourse.getdbt.com/u/Priest)\
**Post date:** [July 31, 2025, 12:41pm UTC](https://discourse.getdbt.com/t/rendering-macro-within-macro/20001/1 "2025-07-31T12:41:30Z")

</div>

```auto

```

## The problem I’m having

Hi,

I’m trying to dynamically build the columns in the “SELECT” query utilizing a customer macro and the model’s YML file. And I’m getting ‘macro’ undefined error.

## The context of why I’m trying to do this

This gives the users to control the value for the column that they want. Even though we declare a standard, that might be satisfactory to the client and this enables them to provide overwrites to a specific column.

## What I’ve already tried

**Desired YML Structure that the user can provide overwrites to** :

```auto
version: 2

models:
  - name: table_name
    description: ""
    tests:
      - model_has_rows:
    columns:
      - name: COLUMN1
        data_type: varchar
        description: ''

      - name: COLUMN2
        data_type: number
        description: ''
        overwrite: "{{ overwrite_macro_name() }}"

```

**Macro that defines the standard structure of the model** :

```auto
{% macro gen_stage_table_name(key) %}
	{# This macro generates the SQL for the table_name stage model #}
	
	{# Check if the key is 'columns' to return the column definitions #}
	{% if key=='columns'%}
		{%- set product_cols = 
			{
                "COLUMN1": "Data",
                "COLUMN2": "Data"
            }
		-%}
		{{ return(product_cols) }}
{% endif %}
{% endmacro %}

```

**Macro that compares the column values** :

```auto
{% macro gen_product_columns(macro_name, supplied_cols) %}
    {%- set filtered_cols = {} -%}
    {% set macro_call = "gen_stage_" ~ macro_name %}
    {% set macro_to_call = context[macro_call] %}
    {%- set product_cols = macro_to_call('columns') -%}
    {# Iterate through supplied_cols and filter based on product_cols #}
    {%- for key, value in supplied_cols.items() -%}
            {%- if key in product_cols -%}
                {%- if value.get('overwrite') %} {# Use the overwrite value if provided #}
                    {% if value.get('macro') %}
                    {%- do filtered_cols.update({key: context.render(value['overwrite'])}) -%} 
                    {% else %}
                    {%- do filtered_cols.update({key: (value['overwrite'])}) -%}
                    {% endif %}
                {%- else %} {# Use the product column definition #}
                    {%- do filtered_cols.update({key: context.render(product_cols[key])}) -%}
                {%- endif %}
            {%- else %} {# If the key is not in product_cols, use the supplied value #}
                {%- do filtered_cols.update({key: context.render(value['overwrite'])}) -%}
            {%- endif %}
    {%- endfor -%}

    {%- for key, value in filtered_cols.items() %}
        {{ value }} AS {{ key }}{%- if not loop.last -%},{%- endif -%}    
    {%- endfor -%}
{% endmacro %}

```

**Final Model File** :

```auto
SELECT DISTINCT
    {{gen_product_columns("table_name", model.columns)}}
FROM SOURCE

```

## Some example code or error messages

```auto
Compilation Error
  Could not render {{ overwrite_macro_name() }}: 'overwrite_macro_name' is undefined

```