Query Variables

What is a variable in GraphQL context?

GraphQL has a first-class way to factor dynamic values out of the query, and pass them as a separate dictionary. These values are called variables. In our case, we are defining the object to be inserted as a mutation.

So let's define the graphql mutation to be used.

Open src/app/Todo/TodoInput.ts and add the following code:

githubsrc/app/Todo/TodoInput.ts
import { Component, OnInit, Input } from '@angular/core';
+ import gql from 'graphql-tag';
+ const ADD_TODO = gql `
+ mutation ($todo: String!, $isPublic: Boolean!) {
+ insert_todos(objects: {title: $todo, is_public: $isPublic}) {
+ affected_rows
+ returning {
+ id
+ title
+ created_at
+ is_completed
+ }
+ }
+ }
+ `;
@Component({
selector: 'TodoInput',
templateUrl: './TodoInput.template.html',
})
export class TodoInput {
...
}

What does this mutation do?

The mutation inserts into todos table with the $objects variable being passed as one todo type.

Awesome! We have defined our first graphql mutation.