- What is a resolver function in GraphQL?
- What is a resolver function?
- Is GraphQL JSON?
- What is GraphQL query?
- Why is it called GraphQL?
- Is GraphQL an API gateway?
- What is Apollo Federation?
- What are GraphQL subscriptions used for?
- What is schema stitching?
- What database does GraphQL use?
- What is the difference between an encoder and a resolver?
- How do you define schema in GraphQL?
What is a resolver function in GraphQL?
A resolver is a function that’s responsible for populating the data for a single field in your schema.
Whenever a client queries for a particular field, the resolver for that field fetches the requested data from the appropriate data source.
A promise that fulfills with data of the required type..
What is a resolver function?
A resolver is a function that resolves a value for a type or field in a schema. Resolvers can return objects or scalars like Strings, Numbers, Booleans, etc. If an Object is returned, execution continues to the next child field.
Is GraphQL JSON?
GraphQL defines a standard grammar for a query language to read/write data. It kind of looks like a neater JSON with just the keys and allows you to pass arbitrary parameters in the query.
What is GraphQL query?
A GraphQL query is used to read or fetch values while a mutation is used to write or post values. In either case, the operation is a simple string that a GraphQL server can parse and respond to with data in a specific format. … GraphQL queries help to reduce over fetching of data.
Why is it called GraphQL?
GraphQL allows us to define a Root Query Type (we’ll refer to it as RootQuery), which defines where a GraphQL query can start when traversing the app data graph. … This is where GraphQL gets its name: GraphQL is a query language that traverses your data graph to produce a query result tree.
Is GraphQL an API gateway?
Specifically, GraphQL allows you to evolve your API naturally without versioning, it provides workable documentation, it avoids the problems of over- and under-fetching, and it offers a convenient way to aggregate data from multiple sources with a single request. …
What is Apollo Federation?
Apollo Federation is our answer for implementing GraphQL in a microservice architecture. It’s designed to replace schema stitching and solve pain points such as coordination, separation of concerns, and brittle gateway code. Federation is based on these core principles: Building a graph should be declarative.
What are GraphQL subscriptions used for?
Get real-time updates from your GraphQL server Like queries, subscriptions enable you to fetch data. Unlike queries, subscriptions maintain an active connection to your GraphQL server (most commonly via WebSocket). This enables your server to push updates to the subscription’s result over time.
What is schema stitching?
Schema stitching is the process of creating a single GraphQL schema from multiple underlying GraphQL APIs. … Merging two remote schemas (github) Custom resolvers: Adding new queries and mutations to an existing remote schema (github) Override existing queries and mutations of a remote schema (github)
What database does GraphQL use?
GraphQL is often confused with being a database technology. This is a misconception, GraphQL is a query language for APIs – not databases. In that sense it’s database agnostic and can be used with any kind of database or even no database at all.
What is the difference between an encoder and a resolver?
Encoders are typically powered with simple DC voltage. Resolvers are “excited” by an AC reference sine wave, typically created with a dedicated resolver power supply; this power supply is typically powered with simple DC voltage.
How do you define schema in GraphQL?
The GraphQL runtime defines a generic graph-based schema to publish the capabilities of the data service it represents….IllustrationStep 1 − Download and Install Required Dependencies for the Project. Create a folder named schema-app. … Step 2 − Create a Schema. … Step 3 − Create Resolver. … Step 4 − Run the Application.