Why server setup enables GraphQL - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a GraphQL schema with a query type.

GraphQL

const schema = new GraphQLSchema({ query: [1] });

Drag options to blanks, or click blank then click option'

AQueryType

BSubscriptionType

CMutationType

DResolverType

Attempts:

3 left

💡 Hint

Common Mistakes

Using MutationType instead of QueryType for the query field.

Leaving the query field undefined.

Confusing subscription with query.

The query field defines the entry point for reading data in GraphQL. It must be set to the query type object.

2fill in blank

medium

Complete the code to create a GraphQL server using Express and the graphqlHTTP middleware.

GraphQL

app.use('/graphql', graphqlHTTP({ schema: schema, graphiql: [1] }));

Drag options to blanks, or click blank then click option'

Atrue

Bfalse

Cnull

Dundefined

Attempts:

3 left

💡 Hint

Common Mistakes

Setting graphiql to false disables the helpful interface.

Using null or undefined causes errors.

Setting graphiql to true enables the GraphiQL interface, which helps test queries in the browser.

3fill in blank

hard

Fix the error in the resolver function by completing the return statement.

GraphQL

const root = { hello: () => [1] };

Drag options to blanks, or click blank then click option'

AHello world!

Bconsole.log('Hello world!')

C'Hello world!'

Dreturn 'Hello world!'

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting quotes around the string.

Using console.log instead of returning a value.

Including the return keyword inside the arrow function shorthand.

The resolver must return a string value. The string needs quotes to be valid.

4fill in blank

hard

Fill both blanks to define a GraphQL ObjectType with a name and a field.

GraphQL

const QueryType = new GraphQLObjectType({ name: '[1]', fields: { greeting: { type: [2] } } });

Drag options to blanks, or click blank then click option'

AQuery

BGraphQLString

CGraphQLInt

DMutation

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Mutation' as the name for the query type.

Using GraphQLInt for a text field.

Confusing the type with the name.

The object type name is usually 'Query' for the root query. The field type for text is GraphQLString.

5fill in blank

hard

Fill all three blanks to create a GraphQL schema with a query type and a resolver.

GraphQL

const schema = new GraphQLSchema({ [1]: QueryType }); const root = { [2]: () => [3] };

Drag options to blanks, or click blank then click option'

Aquery

Bhello

C'Hello from server!'

Dmutation

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'mutation' instead of 'query' in the schema.

Mismatching resolver names with schema fields.

Not returning a string in the resolver.

The schema needs a query field set to the query type. The resolver function named hello returns a greeting string.