What is @nestjs/graphql?
@nestjs/graphql is a module for NestJS that provides integration with GraphQL. It allows developers to build GraphQL APIs using the NestJS framework, leveraging its powerful features like dependency injection, modular architecture, and decorators.
What are @nestjs/graphql's main functionalities?
Schema First Approach
In the schema-first approach, you define your GraphQL schema using the SDL (Schema Definition Language) and then implement the resolvers in your code. This approach is useful for teams that prefer to start with the schema design.
const { GraphQLModule } = require('@nestjs/graphql');
const { join } = require('path');
@Module({
imports: [
GraphQLModule.forRoot({
typePaths: ['./**/*.graphql'],
}),
],
})
export class AppModule {}
Code First Approach
In the code-first approach, you define your GraphQL schema using TypeScript decorators and classes. This approach is useful for teams that prefer to start with the implementation and generate the schema automatically.
const { GraphQLModule } = require('@nestjs/graphql');
const { join } = require('path');
@ObjectType()
class User {
@Field()
id: number;
@Field()
name: string;
}
@Resolver(of => User)
class UserResolver {
@Query(returns => User)
getUser() {
return { id: 1, name: 'John Doe' };
}
}
@Module({
imports: [
GraphQLModule.forRoot({
autoSchemaFile: join(process.cwd(), 'src/schema.gql'),
}),
],
providers: [UserResolver],
})
export class AppModule {}
Resolvers
Resolvers are used to define the logic for fetching data for your GraphQL queries. In this example, a simple resolver is created to return a 'Hello World!' string.
const { Resolver, Query } = require('@nestjs/graphql');
@Resolver('User')
class UserResolver {
@Query(() => String)
sayHello() {
return 'Hello World!';
}
}
@Module({
providers: [UserResolver],
})
export class AppModule {}
Mutations
Mutations are used to modify data on the server. In this example, a mutation is created to handle the creation of a new user.
const { Resolver, Mutation, Args } = require('@nestjs/graphql');
@Resolver('User')
class UserResolver {
@Mutation(() => Boolean)
createUser(@Args('name') name: string) {
// Logic to create a user
return true;
}
}
@Module({
providers: [UserResolver],
})
export class AppModule {}
Other packages similar to @nestjs/graphql
apollo-server
Apollo Server is a community-driven, open-source GraphQL server that works with any GraphQL schema. It is highly flexible and can be used with various Node.js frameworks. Compared to @nestjs/graphql, Apollo Server is more general-purpose and not tied to a specific framework like NestJS.
graphql-yoga
GraphQL Yoga is a fully-featured GraphQL server with focus on easy setup, performance, and great developer experience. It is built on top of Express and Apollo Server. While @nestjs/graphql is tightly integrated with NestJS, GraphQL Yoga offers a more standalone solution.
type-graphql
TypeGraphQL is a library that allows you to create GraphQL APIs using TypeScript classes and decorators. It is similar to the code-first approach in @nestjs/graphql but is framework-agnostic, meaning it can be used with any Node.js framework or even standalone.