Variables In Graphql | Graphql Basics

Overview of Variables in GraphQL

Variables in GraphQL allow you to create dynamic queries by passing parameters into your queries. This makes your queries reusable and more readable.

Key Points:

Variables enable dynamic execution of queries.
They help prevent hardcoding values in queries.
Using variables improves query readability and maintainability.

Using Variables in GraphQL Queries

Defining Variables

To use variables in your queries, you must define them in the query string. Here's how to define and use a variable:


// Example: Defining and using a variable
query getUser($id: ID!) {
  user(id: $id) {
    name
    email
  }
}

Passing Variables

Once variables are defined, you can pass their values when executing the query. Here’s an example:


// Example: Passing variables
{
  "id": "1"
}

Using Variables in Mutations

You can also use variables in mutations to make your code cleaner and more flexible. Here's an example of a mutation using variables:


// Example: Mutation with variables
mutation createUser($name: String!, $email: String!) {
  createUser(name: $name, email: $email) {
    id
    name
  }
}

Best Practices for Using Variables

Follow these best practices when using variables in GraphQL:

Always Define Variable Types: Clearly define the types of your variables for better validation.
Avoid Hardcoding Values: Use variables instead of hardcoded values for flexibility.
Keep Queries Clean: Using variables helps maintain clean and readable queries.

Summary

This guide provided an overview of using variables in GraphQL, including their definition, usage in queries and mutations, and best practices. Utilizing variables effectively can enhance the quality and maintainability of your GraphQL APIs.

GraphQL Basics - Variables in GraphQL