About var function

Variables can be passed from your dbt_project.yml file into models during compilation. These variables are useful for configuring packages for deployment in multiple environments, or defining values that should be used across multiple models within a package.

To add a variable to a model, use the var() function:

my_model.sql

select * from events where event_type = '{{ var("event_type") }}'

If you try to run this model without supplying an event_type variable, you'll receive a compilation error that looks like this:

Encountered an error:
! Compilation error while compiling model package_name.my_model:
! Required var 'event_type' not found in config:
Vars supplied to package_name.my_model = {
}

To define a variable in your project, add the vars: config to your dbt_project.yml file. See the docs on using variables for more information on defining variables in your dbt project.

dbt_project.yml

name: my_dbt_project
version: 1.0.0

config-version: 2

# Define variables here
vars:
  event_type: activation

Variable default values

The var() function takes an optional second argument, default. If this argument is provided, then it will be the default value for the variable if one is not explicitly defined.

my_model.sql

-- Use 'activation' as the event_type if the variable is not defined.
select * from events where event_type = '{{ var("event_type", "activation") }}'