An easier way to use custom parameters in ehrQL

We’ve made it easier to pass custom parameters to ehrQL, so that you can reuse your ehrQL code more effectively.

Parameters can be passed from a pipeline action:

version: '4.0'

actions:
  generate_dataset:
    run: ehrql:v1 generate-dataset dataset_definition.py --output output/dataset.arrow
      --
      --start_date 2025-01-01
    ...

And then defined and used in an ehrQL python file:

from ehrql import get_parameter

start_date = get_parameter("start_date")

For more information on how to use custom parameters in your ehrQL, see the reference documentation and the How To guide

• Link to documentation for An easier way to use custom parameters in ehrQL
• Pull request: opensafely-core/ehrql#2492