Jinja templates

Introduction to dbt

Mike Metzger

Data Engineer

What is a template?

A defined format allowing for substitution of information
Often a text file
Simplifies access and re-use

What is Jinja?

Simple text based templating language
Used in many tools beyond just dbt
{{ ... }} represents a template substitution
dbt has many Jinja functions available for use in projects
Allows for more dynamic usage of dbt
Can use for loops to simplify code

dbt Jinja functions

Some of the many Jinja functions available
- ref: Access models by name
- config: Access configuration settings
- docs: Access documentation information
- Calculations, Loops, etc

Jinja example

Without Jinja

SELECT
COALESCE(start_date, '2025-01-01') as start_date,
COALESCE(update_date, '2025-01-01') as update_date,
COALESCE(end_date, '2025-01-01') as end_date
FROM Events

With Jinja

SELECT
{% for column in ['start_date', 'update_date', 'end_date'] %}
COALESCE({{column}}, '2025-01-01') as {{column}}
{% endfor %}
FROM Events

Let's practice!

Introduction to dbt