Queries Mutations and Fragments

Queries Mutations and Fragments

Queries

Fetching data in a simple, predictable way is one of the core features of Apollo Client. Queries are used to fetch GraphQL data attach the result to your UI. In frontend mobile and dashboard we have written multiple queries in mobile app located inshopping-cart-app/src/apollo/server.js in Dashboard Queries are located in shopping-cart-admin/src/apollo/server.js As an example look into shopping-cart-app/src/apollo/server.js and the constant getNotifications the query is written as

query categories{
    categories{
    _id
    order
    status
    }
}

On line 1 categories is the query name for the frontend while on line 2 categories is the query name for backend. The parameters written inside notifications are output parameters they will be returned by the GraphQL endpoint.

Now let's take a look at another example this time we are going to pass some parameters as input to a query. The constant foods is a simple example for this located at food-delivery-app/src/apollo/server.js

query SubCategoriesById($id:String!){
    subCategoriesById(id:$id){
    _id
    title
    image
    category{
      _id
      title
    }
}

On line 1 SubCategoriesById is the query name for the frontend we are passing a String where it's variable name is id $ sign is used for variable name while ! is used for required field. On line 2 subCategoriesById is the query name for the backend.