GraphQL how to mutate data - graphql

Question

I have a basic schema for mutating some data which looks like
const schema = new graphql.GraphQLSchema({
mutation: new graphql.GraphQLObjectType({
name: 'Remove',
fields: {
removeUser: {
type: userType,
args: {
id: { type: graphql.GraphQLString }
},
resolve(_, args) {
const removedData = data[args.id];
delete data[args.id];
return removedData;
},
},
},
})
});
Looking around google I cant find a clear example of the example query which needs to be sent to mutate.
I have tried
POST -
localhost:3000/graphql?query={removeUser(id:"1"){id, name}}
This fails with error:
{
"errors": [
{
"message": "Cannot query field \"removeUser\" on type \"Query\".",
"locations": [
{
"line": 1,
"column": 2
}
]
}
]
}

Answer 1

In order to post requests from the front-end application it is recommended to use apollo-client package. Say i wanted to validate a user login information:
import gql from 'graphql-tag';
import ApolloClient, {createNetworkInterface} from 'apollo-client';
client = new ApolloClient({
networkInterface: createNetworkInterface('http://localhost:3000/graphql')
});
remove(){
client.mutate({
mutation: gql`
mutation remove(
$id: String!
) {
removeUser(
id: $id
){
id,
name
}
}
`,
variables: {
id: "1"
}
}).then((graphQLResult)=> {
const { errors, data } = graphQLResult;
if(!errors && data){
console.log('removed successfully ' + data.id + ' ' + data.name);
}else{
console.log('failed to remove');
}
})
}
More information about apollo-client can be found here
Have you tried using graphiql to query and mutate your schema?
If you'd like to create a POST request manually you might wanna try to struct it in the right form:
?query=mutation{removeUser(id:"1"){id, name}}
(Haven't tried POSTing myself, let me know if you succeeded, i structured this out of the url when using graphiql)

Answer 2

You have to explicitly label your mutation as such, i.e.
mutation {
removeUser(id: "1"){
id,
name
}
}
In GraphQL, if you leave out the mutation keyword, it's just a shorthand for sending a query, i.e. the execution engine will interpret it as
query {
removeUser(id: "1"){
id,
name
}
}
cf. Section 2.3 of the GraphQL Specification

Answer 3

const client = require("../common/gqlClient")();
const {
createContestParticipants,
} = require("../common/queriesAndMutations");
const gql = require("graphql-tag");
const createPartpantGql = async (predictObj) => {
try {
let resp = await client.mutate({
mutation: gql(createContestParticipants),
variables: {
input: {
...predictObj,
},
},
});
let contestParticipantResp = resp.data.createContestParticipants;
return {
success: true,
data: contestParticipantResp,
};
} catch (err) {
console.log(err.message)
console.error(`Error creating the contest`);
return {
success: false,
message: JSON.stringify(err.message),
};
}
};