Generic tests with parameters in dbt

Introduction

Generic tests with parameters help you check your data for common problems using reusable rules. They save time and keep your data clean.

When you want to check if a column has any missing values in many tables.

When you need to ensure values in a column are unique across rows.

When you want to verify that values in a column belong to a specific list.

When you want to apply the same test with different settings to multiple columns.

Syntax

dbt

version: 2
models:
  - name: your_model
    columns:
      - name: your_column
        tests:
          - test_name:
              param1: value1
              param2: value2

Generic tests are defined once and can accept parameters to customize their behavior.

Parameters allow you to reuse the same test logic for different columns or conditions.

Examples

This runs the built-in unique test on the email column to check for duplicates.

dbt

version: 2
models:
  - name: customers
    columns:
      - name: email
        tests:
          - unique: {}

This test checks if the status column only contains the allowed values.

dbt

version: 2
models:
  - name: orders
    columns:
      - name: status
        tests:
          - accepted_values:
              values: ['shipped', 'pending', 'cancelled']

This test ensures the amount column has no missing values.

dbt

version: 2
models:
  - name: sales
    columns:
      - name: amount
        tests:
          - not_null: {}

Sample Program

This example applies three generic tests with parameters: user_id must be unique and not null, and user_type must be one of the allowed values.

dbt

version: 2
models:
  - name: users
    columns:
      - name: user_id
        tests:
          - unique: {}
          - not_null: {}
      - name: user_type
        tests:
          - accepted_values:
              values: ['admin', 'member', 'guest']

Important Notes

Always check the documentation for the exact parameters each generic test accepts.

You can create your own custom generic tests with parameters for special rules.

Summary

Generic tests with parameters let you reuse test logic easily.

They help keep your data clean by checking common data quality issues.

Parameters customize tests for different columns or rules.