GraphQL 查询返回 null

Question

我运行了这个成功的突变，它被保存到我的 MongoDB 数据库中：

mutation {
  addRecipe(name: "Chole Dhania Masala", category: "Indian", description: "A tasty dish", instructions: "Cook it") {
    name
    category
    description
    instructions
  }
}

但是，当我对其运行查询时：

query {
  getAllRecipes {
    _id
    name
    category
    likes
    createdDate
  }
}

我不清楚我为什么得到：

{
  "data": {
    "getAllRecipes": null
  }
}

这是我的resolvers.js 文件：

exports.resolvers = {
    Query: {
        getAllRecipes: async (root, args, { Recipe }) => {
            const allRecipes = await Recipe.find();
            return allRecipes;
        }
    },
    Mutation: {
        addRecipe: async (root, { name, description, category, instructions, username }, { Recipe }) => {
            const newRecipe = await new Recipe({
                name,
                description,
                category,
                instructions,
                username
            }).save();
            return newRecipe;
        }
    }
};

Answer 1

你有recipes吗？

Query: {
    getAllRecipes: async (root, args, { Recipe }) => {
        const allRecipes = await Recipe.find();
        if (allRecipes) {
          return allRecipes;
        }

        return null;
    }
}