如何使用graphql将动态数量的变量保存到数据库中？

Question

I'm trying to mutate and query dynamic variables. The user has the choice to add as many variables as they want before sending them off to the server. For example, my app is a productivity app that allows a user to add as many metrics as they want to track their goal so if "Gym" is their goal, the metrics would be "running", "bench press", etc. My problem is, I'm unsure how to save them in the database since there is no pre-configured Schema for these user-created variables.

I've managed to send the variables to the back end using the following:

mutation CreateGoal ($title: String!, $description: String, $metric: [Json!]) {
    createGoal(
      data: {
        title: $title
        description: $description
        metric: { set: $metric }
    }
    ){
      id
    }
  } 

Schema:

type Mutation { 
    createGoal(data: CreateGoalInput!): Goal!
}

input CreateGoalInput {
    title: String!
    description: String
    metric: GoalCreatemetricInput
}

input GoalCreatemetricInput {
  set: [Json!]
}

Once the variables arrive in the resolver, it's in the Json format:

{ set: [ 'running', 'bench press' ] }

Normally, I'd simply save the variables through Prisma :

 async createGoal(parent, { data }, { request, prisma }, info) {
        const { title, description, metric } = data && data
        return prisma.mutation.createGoal({
            data: {
                user: {
                    connect: {
                        email: user.email
                    }
                },
                title,
                description,
            }
        }, info)
    },

However, since the number of variables are unknown, how do I save 'metric' into my database?

If I were to try the following:

 async createGoal(parent, { data }, { request, prisma }, info) {
        const { title, description, metric } = data && data
        return prisma.mutation.createGoal({
            data: {
                user: {
                    connect: {
                        email: user.email
                    }
                },
                title,
                description,
                metric,
            }
        }, info)
    },

I get the error:

Error: Variable "$_v0_data" got invalid value [ "running", "bench press" ] at "_v0_data.metric"; Field "0" is not defined by type GoalCreatemetricInput.

If I were to try:

 async createGoal(parent, { data }, { request, prisma }, info) {
        const { title, description, metric } = data && data
        return prisma.mutation.createGoal({
            data: {
                user: {
                    connect: {
                        email: user.email
                    }
                },
                title,
                description,
                metric: metric.set
            }
        }, info)
    },

I get the error:

Error: Variable "$_v0_data" got invalid value ["running", "bench press"] at "_v0_data.metric"; Field "0" is not defined by type GoalCreatemetricInput. Variable "$_v0_data" got invalid value ["Asdfasdf", "Asdfasdf"] at "_v0_data.metric"; Field "1" is not defined by type GoalCreatemetricInput.

Answer 1

I don't think you need to use the Json scalar at all. It looks like you're trying to pass an array of strings so instead of [Json!] you may just need to use [String!] .

input CreateGoalInput {
    title: String!
    description: String
    metric: [String!]
}

Then you should be able to get rid of

input GoalCreatemetricInput {
  set: [Json!]
}

Here you should be able to pass the array of strings to the backend:

mutation CreateGoal ($title: String!, $description: String, $metric: [String!]) {
    createGoal(
      data: {
        title: $title
        description: $description
        metric: $metric 
    }
    ){
      id
    }
  } 

And in your resolover I think all you need to do is:

async createGoal(parent, { data }, { request, prisma }, info) {
        const { title, description, metric } = data && data
        return prisma.mutation.createGoal({
            data: {
                user: {
                    connect: {
                        email: user.email
                    }
                },
                title,
                description,
                metric: { set: metric },
            }
        }, info)
    },