Fields in GraphQL are the fundamental components that allow clients to specify the data they need from a server. They represent individual pieces of data that can be requested for an object.
- In GraphQL , fields are the fundamental units of data that can be requested for an object.
- They represent specific attributes or properties of an object, such as its ID, name, or any other relevant data.
- Fields are the building blocks of GraphQL queries and are used to specify the exact data that clients want to retrieve from the server.
- Fields have different types in GraphQL. Some of them are explained below:
- Scalar fields
- List Fields
- Object Fields
- Custom Scalar Fields
Scalar Fields
- Scalar fields in GraphQL represent primitive data types, such as integers, floats, booleans, and strings.
- Scalar fields hold atomic values and they cannot have subfields.
- Examples of Scalar fields in GraphQL are shown below:
type Student{
id: ID!
name: String!
email: String
}
List Fields
- List Fields has arrays or lists of data of a specific type.
- They are denoted by square brackets followed by the type definition.
- List fields allow returning multiple instances of a particular field.
- Examples of List Fields in GraphQL are shown below:
type Article{
id: ID!
title: String!
tags: [Strings!]!
}
Object Fields
- Object Field are a bit complex as they are used to represent data types which have their own set of fields.
- In Object fields you can traverse related data structure. Nesting is also allowed in Object Fields.
- You can understand Object fields better by understanding the below example.
type Article{
id: ID!
title: String!
author: Author!
}
type Author{
id:ID!
name: String!
email: String!
}
Custom Scalar Fields
- Custom scalar fields represents custom-defined scalar types that are not available in GraphQL.
- Developers can define custom scalar types which can be used to represent specialized data format,such as dates.