Writing Queries — Fields, Nesting, and Aliases

What you'll walk away with

Explain the core ideas behind Writing Queries — Fields, Nesting, and Aliases
Run the sample GraphQL query or code and verify its output
Apply the technique correctly to the Tutorial Platform and production scenarios

Build the mental model

A GraphQL query is a tree-shaped selection set inside curly braces, listing exactly the fields you want. When an object-type field (such as `author`) includes a sub-selection, that becomes a nested query. If you need to call the same field twice with different arguments in one query, an alias (`featured: tutorials`) renames the result key so both can coexist.

Connect it to a real scenario

For the tutorial card component, request `tutorial(id: "42")` with `id`, `title`, and a nested `author { name }`. On the homepage, fetch a featured list and a latest list from the same `tutorials` field in one query using two aliases.

A selection set is a tree of requested fields
Nested fields fetch related data without extra round trips
Aliases let you call the same field under different result keys

Try the working example

graphql

query TutorialCard {
  tutorial(id: "42") {
    id
    title
    author {
      name
    }
  }
  featured: tutorials {
    title
  }
  latest: tutorials {
    title
  }
}

You should see

You can write a query that uses nested field selection and aliases.

5-minute try-it

Query `tutorial(id: "7")` for `title` and nested `lessons { title }`, then call `tutorials` twice under `featured` and `archived` aliases.

One important caution

Leaving off the selection set under an object-type field causes a validation error — only scalar fields can be leaves.

GraphQL — Queries and Mutations — GraphQL

Easy traps

Leaving off the selection set under an object-type field causes a validation error — only scalar fields can be leaves.
Validate sample queries and mutations on a local or test server with recoverable data before applying them to production.

Exercise

Query `tutorial(id: "7")` for `title` and nested `lessons { title }`, then call `tutorials` twice under `featured` and `archived` aliases.

You'll know it worked when: You can write a query that uses nested field selection and aliases.