A Unified GraphQL API

I’m sure you’re already in love with the GraphQL API Space Cloud provides!

Space Cloud lets you build instant GraphQL APIs on any database. It also helps you bring your REST workloads to GraphQL. All this without having to write a single GraphQL resolver or even know how GraphQL works.

In this guide, I’m about to take this GraphQL awesomeness to a whole new level!

In this guide, we will:

Query our database and microservices in a single request
Chain our database and microservice requests to unleash the true power of GraphQL.

Note: Make sure you have followed all the guides in the Space Cloud Basics track. We’ll be building up from there.

Making multiple calls in a single request

We have already seen how we can call multiple endpoints in a single request. Let’s take this a step further. Run the following GraphQL query in the API Explorer:

query {
  trainer @postgres {
    id
    name
    pokemons {
      id
      name
      power
    }
  }

  add(num1: 1, num2: 2) @myapp {
    value
  }

  double(value: 4) @myapp {
    value
  }
}

What we did here is query our database and microservices in a single request. Since all the queries are executed in parallel, it’s super easy to populate the entire page in a single request!

So does the magic ends here? Not really😛.

Chain our database and microservice queries

Have a look at this query:

query {
  trainer @postgres {
    id
    name
    pokemons {
      id
      name
      power
      double(value: "pokemons.power") @myapp {
        value
      }
    }
  }
}

You should get the response as follows:

{
  "trainer": [
    {
      "id": "1",
      "name": "Ash",
      "pokemons": [
        {
          "id": "1",
          "name": "Pikachu",
          "power": 300,
          "double": {
            "value": 600
          }
        },
        {
          "id": "2",
          "name": "Snorlax",
          "power": 500,
          "double": {
            "value": 1000
          }
        }
      ]
    },
    {
      "id": "2",
      "name": "Misty",
      "pokemons": [
        {
          "id": "3",
          "name": "Psyduck",
          "power": 250,
          "double": {
            "value": 500
          }
        },
        {
          "id": "4",
          "name": "Staryu",
          "power": 350,
          "double": {
            "value": 700
          }
        }
      ]
    }
  ]
}

What we did here is query the database, then chain its result with the double endpoint, all in a single request. It didn’t matter if the database query returns an array or an object, Space Cloud handles the nuances to give you a standard API.

We could have chained one database result with another, throw in some services here and there and bam!! Everything would work just as smoothly.

What this lets us do in essence is create runtime pipeline which is orchestrated by Space Cloud based on the GraphQL query🤓.

To sum up, here are the advantages of the GraphQL layer in Space Cloud:

Instant APIs for any database without writing any code.
Instant Rest to GraphQL without modifying any existing code.
Chain database and microservice responses to form data pipelines on the fly.

Many of you must be wondering about the security implications of this, which is a valid point.

Space Cloud offers a robust security module to protect each database and microservice call being made. You can find more about it from our security guide.

Next steps

We saw the basics of deployments, database and services in the current track. There is a lot more you can do with Space Cloud. Some of the things include:

File storage backed by Amazon S3 or Google Cloud Storage
Trigger endpoints on Database and File storage events
Ability to queue custom events and trigger endpoints based on them
A robust security module to write powerful rules to secure all functionalities.

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