Dynamic where clauses

[mhpaler]

I'm only first level brown belt in Subgraph/GraphQL so not even sure a feature like this makes sense for the graph-client, but here goes.

I'm finding myself writing duplicate queries to handle different where clauses, and obviously this feels redundant and clunky. Doing a bit of research I came across this interesting article which describes a generic way to handle passing different filter clauses into a single query from a node based GraphQL api client.

https://dev.to/mgustus/filtering-graphql-query-using-typescript-and-typeorm-2l49

Curious if this, or something like it, would make sense for the graph-client?

[mhpaler]

In context to this, question, can we do something like this:

query get_items($where: SomeOtherType) {
  items(where: $where) {
    name
  }
}

Where SomeOtherType could have any shape we want? If so, where & how would one define SomeOtherType?

[dotansimha]

Hi @mpaler !
You can leverage the concept of GraphQL variables to achieve that.
First, you need to find the actual GraphQL input type that's defined for the where argument you with to match, and then use that input type for your GraphQL query, as a variable (similar to the example you shared). You can do that with GraphiQL, or just introspect the schema and check the API docs of your field.

For example, for this Subgraph, you can see in the docs that the User_filter input type is used for the where:

So you can write a query that expects this input type as a variable, and then match it to the where argument

query filteredUsers($usersFilter: User_filter) { # define the variable
  users(where: $usersFilter) { # pair it with the argument
    id
    liquidityPositions {
      id
      pair {
        token0 {
          id
        }
        token1 {
          id
        }
      }
    }
  }
} 

Now, when you run your GraphQL query, you can use this single GraphQL query, but with different (=dynamic) variables for each filter that you might need:

This is the best practice in GraphQL, also because the query remains static, and only the value of variables changes every time.

[mhpaler]

@dotansimha thank you!! Been going in circles for two days trying to figure out how I would adjust my schema so I could pass in a filter argument of any shape. This completely makes sense and solves it!!