GraphQL Variables Explained Simply

Unlock the Power of GraphQL Variables

GraphQL has taken the development world by storm, offering a revolutionary way to query APIs. At the heart of this technology lies a crucial concept: variables. In this article, we’ll dive into the world of GraphQL variables, exploring their benefits, uses, and how they can elevate your development experience.

What are GraphQL Variables?

In GraphQL, variables allow you to reuse the same query or mutation with different arguments. This means you can write a single query that can be used multiple times with varying parameters, making your code more efficient and flexible.

Getting Started with GraphQL Variables

To demonstrate the power of variables, we’ll use the GitHub API, a publicly available API that’s perfect for testing and learning. Open the GitHub API explorer (https://developer.github.com/v4/explorer/) and sign in to your GitHub account to run queries.

Querying with Variables

Let’s start with a simple query that accepts arguments as parameters. We’ll query for a repository name and owner ID. By using variables, we can rewrite this query to accept dynamic values. This allows the client to reuse the same query with different arguments, making it more versatile and efficient.

The Three-Step Process

To use variables in your query or mutation, follow these three steps:

1. Replace static values with $variableName.
2. Declare $variableName as one of the variables accepted by the query.
3. Pass variableName: value in a separate, transport-specific (usually JSON) variables dictionary.

Mutations with Variables

Variables aren’t limited to queries; they can also be used with mutations. Let’s write a mutation to update our user status on GitHub. By passing arguments as variables, we can reuse this mutation with different values.

Default Variables

GraphQL also provides a way to assign default values to variables. This default value is used when no variable values are defined explicitly. This works similarly to a function taking a default value as an argument in a programming language.

The Benefits of Variables

So, why are variables essential in GraphQL? They offer three significant benefits:

• Reuse: Variables allow you to reuse the same queries and mutations with different parameters and values.
• Dynamic Queries: With variables, GraphQL supports dynamic queries that can change based on the variables passed to it.
• Flexibility: Variables provide developers with the flexibility they need while querying for data.

Take Your GraphQL Skills to the Next Level

Mastering GraphQL variables is just the beginning. To learn more about GraphQL and get a comprehensive overview, check out our course, GraphQL: The Big Picture. Stay tuned for more articles and resources on GraphQL, and don’t forget to share your thoughts in the comments below!