About builtins Jinja variable
The builtins
variable exists to provide references to builtin dbt context methods. This allows macros to be created with names that mask dbt builtin context methods, while still making those methods accessible in the dbt compilation context.
The builtins
variable is a dictionary containing the following keys:
Usage
Using the builtins
variable in this way is an advanced development workflow. Users should be ready to maintain and update these overrides when upgrading in the future.
From dbt v1.5 and higher, use the following macro to override the ref
method available in the model compilation context to return a Relation with the database name overriden to dev
.
It includes logic to extract user-provided arguments, including version
, and call the builtins.ref()
function with either a single modelname
argument or both packagename
and modelname
arguments, based on the number of positional arguments in varargs
.
Note that the ref
, source
, and config
functions can't be overridden with a package. This is because ref
, source
, and config
are context properties within dbt and are not dispatched as global macros. Refer to this GitHub discussion for more context.
{% macro ref() %}
-- extract user-provided positional and keyword arguments
{% set version = kwargs.get('version') or kwargs.get('v') %}
{% set packagename = none %}
{%- if (varargs | length) == 1 -%}
{% set modelname = varargs[0] %}
{%- else -%}
{% set packagename = varargs[0] %}
{% set modelname = varargs[1] %}
{% endif %}
-- call builtins.ref based on provided positional arguments
{% set rel = None %}
{% if packagename is not none %}
{% set rel = builtins.ref(packagename, modelname, version=version) %}
{% else %}
{% set rel = builtins.ref(modelname, version=version) %}
{% endif %}
-- finally, override the database name with "dev"
{% set newrel = rel.replace_path(database="dev") %}
{% do return(newrel) %}
{% endmacro %}
Logic within the ref macro can also be used to control which elements of the model path are rendered when run, for example the following logic renders only the schema and object identifier, but not the database reference i.e. my_schema.my_model
rather than my_database.my_schema.my_model
. This is especially useful when using snowflake as a warehouse, if you intend to change the name of the database post-build and wish the references to remain accurate.
-- render identifiers without a database
{% do return(rel.include(database=false)) %}