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Generating a dummy dataset

In this section, you will generate a dummy dataset.

Generate a dummy dataset🔗

In the terminal, type

opensafely exec ehrql:v0 generate-dataset dataset_definition.py

and press Enter.

The terminal will fill with a dummy dataset in CSV format. Scroll up to see the column headers; notice that two column headers correspond to the two columns — asthma_med_date and asthma_med_code — that you added to the dataset definition.

A screenshot of VS Code, showing the terminal after the opensafely exec command was run

The anatomy of an OpenSAFELY command

What do the parts of the OpenSAFELY command opensafely exec ehrql:v0 generate-dataset dataset_definition.py do?

  • opensafely exec executes an OpenSAFELY action independently of other OpenSAFELY actions
  • ehrql is the OpenSAFELY action to execute
  • v0 is the major version of the ehrQL action
  • generate-dataset is the ehrQL command to generate a dataset from a dataset definition
  • dataset_definition.py is the dataset definition