Is it possible to run join query in supabase with GraphQL?

Question

I have two tables in supabase

• category : id (int4 (pk)), name (text)
• product : id (int4 (pk)), name (text), price (int8), category_id (fk with id of category);

What will be the query in my resolver function to fetch category with all related products?

Necessary code is shown here. I tried .join but it is not a function in supabase - does any have a solution?

My category.schema.js is

module.exports = `
  type Category {
    id: Int
    name: String!
    product:Product!
  }
  type Query {
    getCategoryList: [category_product]!
    getCategory(id: Int!): Category
  }
  type Mutation {
    addCategory(name: String!): Category
    updateCategory(id:ID!,name: String!): Category
    deleteCategory(id:ID!): Category
  }
`;

product.schema.js:

module.exports = `
type Product {
  id: Int
  name: String!
  price: Int!
  isDeleted: Boolean!
  category: Category!
}
  type Query {
    getProductList: [Product]
    getProduct(id: Int!): Product
  }
  type Mutation {
    addProduct(name: String!, price: Int!, category: Int!): Product
    updateProduct(id: Int!,name:String,price:Int!): Product
    deleteProduct(id:ID!): Product
  }
`;

category.resolver.js:

const { isEmpty } = require("lodash");
const supabase = require("../../supabase");

let validator = {};

module.exports = {
  Query: {
    getCategoryList: async () => {
     try {
      const {data,error} = await supabase.from("category").select(`id,name,product(id,name,price)`);
      if (error) {
        throw new Error(error.message);
      }
      console.log("data :",data);
      return data;
     } catch (error) {
      console.log("Error",error);
      return null;
     }
    },
    getCategory: async (parent, args) => {
      const id = args.id;
      if (!/^[0-9a-fA-F]{24}$/.test(id)) {
        validator.error = ERROR_MSG.INVALID_ID;
        throw new ValidationException(validator);
      }
      const result = category
        .findById(id)
        .populate([
          {
            path: "productId",
            select: "name price isDeleted _id",
          },
        ])
        .select("_id name productId");
      if (!result) {
        validator.category = ERROR_MSG.CATEGORY_ERROR;
        throw new ValidationException(validator);
      }
      return result;
    },
  },
  Mutation: {
    addCategory: async (parent, args) => {
      const name = args.name;
      // console.log("name", name);
      if (!/^[a-zA-Z ]+$/.test(name)) {
        validator.name = WARNING_MSG.CATEGORY_NAME_WARNING;
      }
      const categotyExists = await category.findOne({ name });
      if (categotyExists) {
        validator.category = WARNING_MSG.CATEGORY_WARNING;
      }
      if (!isEmpty(validator)) {
        throw new ValidationException(validator);
      } else {
        let categories = await category.create({
          name: args.name,
        });
        return { categories };
      }
    },
    updateCategory: async (parent, args) => {
      const { id, name } = args;
      const categotyExists = await category.findOne({ name });
      if (categotyExists) {
        validator.error = WARNING_MSG.CATEGORY_WARNING;
        // console.log("Hii", validator);
      } else {
        if (/^[0-9a-fA-F]{24}$/.test(id)) {
          const result = category.findByIdAndUpdate(
            id,
            {
              name: args.name,
            },
            { new: true }
          );
          return result;
        } else {
          validator.error = ERROR_MSG.CATEGORY_ERROR;
        }
      }
      if (!isEmpty(validator)) {
        // console.log("hii");
        throw new ValidationException(validator);
      }
    },
    deleteCategory: async (parent, args) => {
      const id = args.id;
      if (id) {
        const result = product.findByIdAndUpdate(
          id,
          {
            isDeleted: true,
          },
          { new: true }
        );
        return result;
      }
    },
  },
};

I try using .join but it shows me join is not a function

Answer 1

To perform joins in Supabase, you just nest the objects within your select() method like this:

const { data, error } = await supabase
  .from('category')
  .select('*, product(*)')

BTW, Supabase has itsown GraphQL feature, so you don't have to write your own resolver by yourself.

https://supabase.com/blog/graphql-now-available