Simple tips to avoid overfetching from your GraphQL API

Overfetching in GraphQL can lead to unnecessary data transfer and impact performance. Let's explore simple examples to efficiently design your queries and avoid overfetching from the server.

Explicit field selection

Let's say we have a GraphQL API to fetch the product details. The product details include the name, description, price and the list of reviews. The GraphQL query to fetch the product details will look like this.

# Overfetching
query {
  product(id: "456") {
    name
    description
    price
    reviews {
      rating
      comment
      user {
        name
        email
      }
    }
  }
}

# Avoid Overfetching
query {
  product(id: "456") {
    name
    price
    reviews {
      rating
      comment
    }
  }
}

By explicitly specifying only the fields needed for a particular operation, unnecessary data is excluded from the response. This reduces the amount of data transferred over the network, improving query performance and reducing overfetching.

Paginating the lists

Implement pagination for efficient list queries. Let's say we have a GraphQL API to fetch the list of orders.

# Fetching all orders of a customer (Overfetching)
query {
  customer(id: "789") {
    orders {
      id
      total
      items {
        name
        quantity
      }
    }
  }
}

# Efficient pagination
query {
  customer(id: "789") {
    orders(first: 5) {
      id
      total
      items {
        name
        quantity
      }
    }
  }
}

By paginating the list, we can fetch only the required number of items from the server.

Hope this article helps you to avoid overfetching from your GraphQL API. please follow me on my twitter for more content 🚀.