H17 Look up brokers

Use your current course session. Preparation and course runner · R script ↓

H17 Look up brokers

Goal: Add a second attribute.

Prerequisites: H16.

Extend the same recipe approach and revise the output contract.

training_step(
  "H17",
  {
    brokers <- data.frame(
      broker_id = 1:2,
      broker_name = c("Broker A", "Broker B")
    )
    enriched_contract <- dr_contract_update(
      linked_contract,
      version = "2.0.0",
      columns = c(broker_name = "character")
    )
    enrichment_recipe <- customer_recipe |>
      dr_step_lookup(brokers, by = "broker_id")
    enriched_product <- dr_product(
      "policies.enriched",
      linked_policies,
      contract = enriched_contract
    ) |>
      dr_add_recipe(enrichment_recipe)
    enriched_rows <- dr_collect(dr_run(enriched_product, write = FALSE))
    print(enriched_rows)
    stopifnot(nrow(enriched_rows) == 6L, !anyNA(enriched_rows$broker_name))
  },
  needs = c("H16")
)

Expected result: Broker names without multiplying rows.

Task: Why is a duplicate broker_id in brokers a problem?