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Comment by NonNefarious | Hacker News Reader

I thought it was supposed to do this, but then discovered that it has no way to express joins.

Has this been addressed? I don't see how you can decouple the back-end data from front-end queries without that.

You can do something like this. This query can be created and run on the client:

``` const SAMPLE_JOIN_QUERY = gql` query ($main_data_id: String!) { mainData( main_data_id: $main_data_id) { id main_data_field_1 main_data_field_2 main_data_field_3 related_data{ related_data_field_1 related_data_field_2 related_data_field_3 } } } `; ```

in other words, it's up to the folks writing the resolvers to manifest and implement that join as a nested field.

Dataloader does this IIRC

Which means a lot of the time they end up just caching as hard as they can and hoping that's good enough.

(which is often, honestly, an entirely rational decision in terms of prioritising limited resources, but still makes me sad)

https://news.ycombinator.com/formatdoc may interest you

    const SAMPLE_JOIN_QUERY = gql`
    query ($main_data_id: String!) {
      mainData( main_data_id: $main_data_id) { 
        id main_data_field_1 main_data_field_2 main_data_field_3 
        related_data {
          related_data_field_1 related_data_field_2 related_data_field_3
        }
      } 
    }`;

Thanks!

Right, but on the backend someone had to think ahead of time that somebody would want to JOIN between those two types, and remember to put the field in place, and implement the JOIN.

Reply on news.ycombinator.com