fail_calc

▶Changelog

Test queries are written to return a set of failing records, ones not matching the expectation or assertion declared by that test: duplicate records, null values, etc.

Most often, this is the count of rows returned by the test query: the default value of fail_calc is count(*). But it can also be a custom calculation, whether an aggregate calculation or simply the name of a column to be selected from the test query.

Most tests do not use the fail_calc config, preferring to return a count of failing rows. For the tests that do, the most common place to set the fail_calc config is right within a generic test block, alongside its query definition. All the same, fail_calc can be set in all the same places as other configs.

For instance, you can configure a unique test to return sum(n_records) instead of count(*) as the failure calculation: that is, the number of rows in the model containing a duplicated column value, rather than the number of distinct column values that are duplicated.

• Specific test
• One-off test
• Generic test block
• Project level

Configure a specific instance of a generic (schema) test:

models/<filename>.yml

version: 2

models:
  - name: my_model
    columns:
      - name: my_columns
        tests:
          - unique:
              config:
                fail_calc: "sum(n_records)"