> ## Documentation Index
> Fetch the complete documentation index at: https://cubed3-feat-druid-driver-streaming.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Drilldowns

> Configure measure drill members in the data model and invoke `ResultSet.drillDown()` to fetch detail rows behind an aggregate.

Drilldowns are a powerful feature to facilitate data exploration. It allows
building an interface to let users dive deeper into visualizations and data
tables. See [`ResultSet.drillDown()`][ref-cube-client-ref-resultset-drilldown]
on how to use this feature on the client side.

A drilldown is defined on the [measure][ref-schema-ref-measures] level in your
data model. It’s defined as a list of dimensions called **drill members**. Once
defined, these drill members will always be used to show underlying data when
drilling into that measure.

Let’s consider the following example of our imaginary e-commerce store. We have
the `orders` cube, which describes orders in our store. It’s connected to
`users` and `products`.

<CodeGroup>
  ```yaml title="YAML" theme={null}
  cubes:
    - name: orders
      sql_table: orders

      joins:
        - name: users
          relationship: many_to_one
          sql: "{CUBE}.user_id = {users.id}"

        - name: products
          relationship: many_to_one
          sql: "{CUBE}.product_id = {products.id}"

      measures:
        - name: count
          type: count
          # Here we define all possible properties we might want
          # to "drill down" on from our front-end
          drill_members:
            - id
            - status
            - products.name
            - users.city

      dimensions:
        - name: id
          sql: id
          type: number
          primary_key: true
          public: true

        - name: status
          sql: status
          type: string
  ```

  ```javascript title="JavaScript" theme={null}
  cube(`orders`, {
    sql_table: `orders`,

    joins: {
      users: {
        relationship: `many_to_one`,
        sql: `${CUBE}.user_id = ${users.id}`
      },

      products: {
        relationship: `many_to_one`,
        sql: `${CUBE}.product_id = ${products.id}`
      }
    },

    measures: {
      count: {
        type: `count`,
        // Here we define all possible properties we might want
        // to "drill down" on from our front-end
        drill_members: [id, status, products.name, users.city]
      }
    },

    dimensions: {
      id: {
        type: `number`,
        sql: `id`,
        primary_key: true,
        public: true
      },

      status: {
        type: `string`,
        sql: `status`
      }
    }
  })
  ```
</CodeGroup>

You can follow [this tutorial][blog-drilldown-api] to learn more about building
a UI for drilldowns.

[ref-cube-client-ref-resultset-drilldown]: /reference/javascript-sdk/reference/cubejs-client-core#drilldown

[blog-drilldown-api]: https://cube.dev/blog/introducing-a-drill-down-table-api-in-cubejs/

[ref-schema-ref-measures]: /reference/data-modeling/measures