In GraphQL, mutations are used for modifying data on the server. Unlike queries that retrieve data, mutations are responsible for creating, updating, and deleting data. Mutations are executed using the mutation keyword followed by the name of the mutation operation.

Let's take a look at an example mutation to create a new user:

mutation {
  createUser(input: {
    name: "John Smith",
    email: "john@example.com",
    password: "password123"
  }) {
    id
    name
    email
  }
}

In this example, the createUser mutation takes an input object with the user's name, email, and password. The mutation then returns the id, name, and email of the newly created user.

To update data, mutations follow a similar pattern. You specify the update operation, provide the necessary input, and specify the fields to be returned. For delete operations, you can use the delete keyword followed by the type you want to delete, and provide any required arguments.

mutation {
  updateUser(id: "123", input: {
    name: "John Doe",
    email: "john.doe@example.com"
  }) {
    id
    name
    email
  }
}

mutation {
  deleteUser(id: "123")
}

When working with mutations, it's crucial to validate input data and handle errors appropriately. GraphQL provides mechanisms to define input types for mutations and perform input validation. You can also handle errors using custom logic or error handling libraries.

Remember, mutations are essential for manipulating data in your GraphQL server. Now that you understand the basics, let's dive deeper into GraphQL and learn more advanced topics in the next post!

Keep up the great work and keep learning!