Running tests with dbt test - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a dbt test run with a failing test

What is the output shown when you run dbt test and one of the tests fails due to a uniqueness violation?

dbt

dbt test

A No tests found to run in the project.

B Test failed: uniqueness test on column 'user_id' in model 'orders' failed with 3 duplicate rows found.

C SyntaxError: invalid syntax in dbt test command.

D All tests passed successfully with no errors.

💡 Hint

Think about what dbt reports when a uniqueness test fails.

When a uniqueness test fails, dbt reports the test name, the model and column tested, and the number of failing rows.

🧠 Conceptual

intermediate

Purpose of dbt test command

What is the main purpose of running dbt test in a dbt project?

A To run data quality checks defined as tests on models and sources.

B To generate documentation for the dbt project.

C To deploy the dbt project to production environment.

D To compile SQL models into tables and views.

💡 Hint

Think about what tests in dbt are used for.

dbt test runs tests that check data quality and integrity, such as uniqueness, not null, and custom tests.

❓ data_output

advanced

Result of a custom test returning rows

You define a custom test in dbt that returns rows where order_amount is negative. What does dbt test output if 5 rows violate this condition?

dbt

select * from {{ ref('orders') }} where order_amount < 0

A Test passed: no rows returned.

B Runtime error: invalid SQL syntax.

C Test skipped: no test defined.

D Test failed: 5 rows returned violating the condition.

💡 Hint

Custom tests fail when they return any rows.

dbt tests fail if the SQL query returns any rows, indicating data issues.

🔧 Debug

advanced

Error when running dbt test with missing test file

You run dbt test but get an error: Compilation Error: Could not find test file 'not_null_user_id.sql'. What is the cause?

A The model 'user_id' does not exist in the project.

B The database connection is not configured properly.

C The test file is missing or not placed in the correct tests directory.

D The dbt version is outdated and does not support tests.

💡 Hint

Check where dbt expects test files to be located.

dbt looks for test SQL files in the tests directory; if missing, it raises a compilation error.

🚀 Application

expert

Interpreting dbt test summary output

After running dbt test, you see this summary:

PASS 1/3 tests
FAIL 2/3 tests
- test_not_null on model customers
- test_unique on model orders

What should you do next?

A Investigate the failing tests to understand data quality issues and fix them.

B Ignore the failures since one test passed.

C Delete the failing tests to avoid errors in future runs.

D Run <code>dbt run</code> to overwrite the data and fix tests automatically.

💡 Hint

Failing tests indicate data problems that need attention.

Failing tests show data quality issues; you should investigate and fix the root causes.