Calling macros across projects in dbt

Introduction

Sometimes you want to reuse code from another project to save time and keep things neat. Calling macros across projects lets you do that easily.

You have a common calculation macro in one project and want to use it in another project.

You want to keep shared logic in a central project and call it from multiple other projects.

You are working on multiple dbt projects and want to avoid copying the same macro code.

You want to update a macro in one place and have all projects use the updated version automatically.

Syntax

dbt

{{ project_name.macro_name(args) }}

You use the project name as a prefix to call the macro from another project.

Make sure the other project is listed as a dependency in your packages.yml file.

Examples

This calls the calculate_discount macro from the other_project project, passing price and discount_rate as arguments.

dbt

{{ other_project.calculate_discount(price, discount_rate) }}

This sets a variable result by calling the format_date macro from the external_project.

dbt

{% set result = external_project.format_date(order_date) %}

Sample Program

This example shows how to add a shared macros project as a package, then call its calculate_tax macro in your model SQL.

dbt

# In packages.yml of your current project:
packages:
  - git: "https://github.com/your_org/shared_macros.git"
    revision: main

# In your model SQL file:
{{ shared_macros.calculate_tax(price, tax_rate) }}

# In shared_macros project, macro defined as:
# {% macro calculate_tax(price, tax_rate) %}
#   {{ price * tax_rate }}
# {% endmacro %}

Important Notes

Always add the external project to packages.yml and run dbt deps to install it.

Macros must be public (not private) to be called across projects.

Use the exact project name as defined in dbt_project.yml of the external project.

Summary

Calling macros across projects helps reuse code and keep projects clean.

You must add the other project as a dependency in packages.yml.

Use {{ project_name.macro_name(args) }} syntax to call the macro.

Practice

1. What is the main reason to call macros across different dbt projects?

easy

A. To make the project run slower

B. To increase the size of the project

C. To reuse code and keep projects organized

D. To avoid using any dependencies

Solution

1. Step 1: Understand the purpose of macros

   Macros are reusable pieces of code that help avoid repetition.

2. Step 2: Recognize the benefit of calling macros across projects

   Calling macros across projects allows sharing code, which keeps projects clean and organized.

3. Final Answer:

   To reuse code and keep projects organized -> Option C

4. Quick Check:

   Code reuse = To reuse code and keep projects organized [OK]

Hint: Macros help reuse code across projects easily [OK]

Common Mistakes:

• Thinking macros increase project size
• Believing macros slow down the project
• Ignoring the need for dependencies

2. Which syntax correctly calls a macro named calculate_total from a project named sales_project?

easy

A. {{ sales_project.calculate_total() }}

B. {{ calculate_total() }}

C. {% sales_project.calculate_total() %}

D. {{ sales_project->calculate_total() }}

Solution

1. Step 1: Recall the correct macro call syntax

   Macros from other projects are called using {{ project_name.macro_name() }}.

2. Step 2: Match the syntax to the options

   {{ sales_project.calculate_total() }} uses the correct dot notation and double curly braces.

3. Final Answer:

   {{ sales_project.calculate_total() }} -> Option A

4. Quick Check:

   Use dot notation inside {{ }} = {{ sales_project.calculate_total() }} [OK]

Hint: Use {{ project_name.macro_name() }} to call macros [OK]

Common Mistakes:

• Using {% %} instead of {{ }} for macro calls
• Missing the project name before the macro
• Using incorrect symbols like ->

3. Given the following packages.yml snippet and macro call, what will happen?

packages:
  - package: sales_project
    version: 1.0.0

-- In a model SQL file:
SELECT {{ sales_project.calculate_discount(100) }} AS discount_amount

medium

A. The macro will run and return the discount value

B. Error because the macro call syntax is wrong

C. Error because sales_project is not added as a dependency

D. The SQL will run but ignore the macro call

Solution

1. Step 1: Check the packages.yml for dependencies

   The sales_project is listed as a dependency, so it is available.

2. Step 2: Verify the macro call syntax

   The macro is called correctly using {{ sales_project.calculate_discount(100) }}.

3. Final Answer:

   The macro will run and return the discount value -> Option A

4. Quick Check:

   Dependency + correct syntax = macro runs [OK]

Hint: Add project in packages.yml before calling macros [OK]

Common Mistakes:

• Forgetting to add dependency in packages.yml
• Using wrong macro call syntax
• Assuming macro calls run without dependencies

4. You try to call a macro from another project but get an error. Which of these is the most likely cause?

medium

A. The macro name is misspelled in the call

B. You used single curly braces instead of double

C. The macro is called without parentheses

D. The other project is not listed in packages.yml

Solution

1. Step 1: Identify common errors in cross-project macro calls

   Missing the other project in packages.yml means dbt cannot find the macro.

2. Step 2: Compare other options

   Misspelling or syntax errors cause different errors, but missing dependency is most common.

3. Final Answer:

   The other project is not listed in packages.yml -> Option D

4. Quick Check:

   Missing dependency = macro call error [OK]

Hint: Always add dependencies in packages.yml first [OK]

Common Mistakes:

• Ignoring packages.yml dependencies
• Using wrong macro call syntax
• Forgetting parentheses in macro calls

5. You want to call a macro format_date from a project utils_project inside your project. You added utils_project in packages.yml. Which is the correct way to pass a date string '2024-01-01' to the macro and use its result in a model?

hard

A. SELECT {{ utils_project.format_date(`2024-01-01`) }} AS formatted_date

B. SELECT {{ utils_project.format_date("2024-01-01") }} AS formatted_date

C. SELECT {{ utils_project.format_date(2024-01-01) }} AS formatted_date

D. SELECT {{ utils_project.format_date('2024-01-01') AS formatted_date }}

Solution

1. Step 1: Confirm dependency is added

   utils_project is added in packages.yml, so macro can be called.

2. Step 2: Check correct string passing in macro call

   Strings in Jinja macros should be double-quoted inside {{ }} to avoid syntax issues.

3. Step 3: Validate SQL syntax

   SELECT {{ utils_project.format_date("2024-01-01") }} AS formatted_date correctly uses double quotes inside the macro call and proper SQL aliasing.

4. Final Answer:

   SELECT {{ utils_project.format_date("2024-01-01") }} AS formatted_date -> Option B

5. Quick Check:

   Double quotes for strings in macro calls = SELECT {{ utils_project.format_date("2024-01-01") }} AS formatted_date [OK]

Hint: Use double quotes for string args inside {{ }} [OK]

Common Mistakes:

• Using unquoted strings causing errors
• Incorrect SQL alias syntax
• Missing quotes or wrong quote types