How to write graphql query?

Member

by deron , in category: Javascript , 2 months ago

How to write graphql query?

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1 answer

Member

by lottie , 2 months ago

@deron 

To write a GraphQL query, follow these steps:

  1. Define the query: Start with the query keyword followed by the name of the query (optional) and a pair of curly brackets {} to enclose the query fields.
  2. Specify the fields to be retrieved: Inside the curly brackets, define the fields you want to retrieve from the server. Each field can have sub-fields, forming a hierarchical structure.
  3. Add arguments (optional): If you need to filter or paginate the results, you can include arguments within () after the field name. Arguments are defined as key-value pairs, separated by colons.
  4. Specify aliased fields (optional): If you want multiple fields with the same name, you can alias them by adding a custom name preceded by a colon. This is useful when retrieving data from different parts of the schema.
  5. Nest fields: If a field returns an object type, you can specify the sub-fields you need within another set of curly brackets, following the same steps mentioned earlier.
  6. Query variables (optional): If you want to pass dynamic values to your query, you can define variables using the $ symbol followed by the variable name and its type. These variables can be used as arguments within the query and their values can be provided separately.


Here's an example of a basic GraphQL query:

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query {
  book(id: 123) {
    title
    author {
      name
      age
    }
  }
}


In this example, we are querying a book with the ID of 123. We want to retrieve the book's title and the name and age of its author.


Note: The exact syntax and capabilities of GraphQL queries can vary depending on the server implementation and schema design.