GraphQL Resolvers
GraphQL resolvers are functions that define how to fetch the data for each field in a GraphQL schema, mapping schema fields to data sources like databases or APIs. They are executed in response to GraphQL queries to retrieve and return the requested data, handling the logic for data fetching and transformation. Resolvers form the core of a GraphQL server's execution engine, enabling flexible and efficient data retrieval.
Developers should learn GraphQL resolvers when building GraphQL APIs to implement custom data-fetching logic, integrate with various backends, and optimize performance through techniques like batching or caching. They are essential for handling complex queries, mutations, and subscriptions, making them crucial for applications requiring precise control over data flow, such as real-time systems or microservices architectures.