How do you create parameterized graphql queries?

Users GraphQL
1

In my project, I have a list of events. I want to be able to filter them in various ways. For example:

  • Get the events where the virtual event URL is NOT an empty string.
  • Get events that fall between two dates.
  • Get events within a radius of an address.

I know these filters require custom code to be written. I just don’t know where to put it. I was reading this doc: https://dgraph.io/docs/graphql/custom/dql/

The above doc uses a complex example with two steps. It first counts the number of a user’s followers, then sorts tweets by the number of followers of the author. I can’t tell if this applies to my use case or not.

So, what is the best way to create parameterized queries?

2

What is your example schema? None of these should require custom dql and can be done with simple queries using filters.

type Event {
  id: ID!
  url: String @search(by: [hash])
  date: DateTime! @search
  location: Point @search
}
  1. filter: { not: { url: { eq: "" } } }
  2. filter: { date: { between: { min: "2020-01-01", max: "2020-02-01" } } }
  3. filter: { location: { near: { coordinate: { latitute: 37.771935, longitude: -122.469829 }, distance: 1000 } } }
3

My schema was basically the same as your example. When I tried those types of queries I got the error:

Field "virtualEventUrl" is not defined by type EventFilter.

My problem was that I needed to add the search annotation to the virtualEventUrl field:

@search(by: [hash])

Now it works. Thank you.

Created a docs PR. Docs(GraphQL): Emphasize that @search annotation is required for filtering on predicates by catherineluse · Pull Request #247 · dgraph-io/dgraph-docs · GitHub