Readquery

Readquery is a generic term used in computer science to refer to an operation or function whose purpose is to retrieve data from a data source without performing updates or other side effects. The exact form and capitalization vary by language and framework (readQuery, ReadQuery, or readquery). In database systems, read queries typically correspond to SELECT statements or read-only transactions; they may include filters, projections, joins, sorting, and pagination, and are designed to be non-destructive and potentially idempotent.

In GraphQL ecosystems, readQuery is a specific API in client-side caches such as Apollo Client. It allows reading data for a previously executed query from the normalized cache, enabling efficient state management and offline or optimistic UI updates without issuing a network request. It contrasts with writeQuery or mutation operations that alter data and the cache.

In broader software development, read queries are common across APIs that separate read paths from write paths. They may rely on caching layers, materialized views, or read replicas to scale read throughput. Access to read queries can be governed by permissions and data-consistency guarantees, and they may support features like pagination, field projection, filtering, and partial results.

See also: writeQuery, readFragment, SQL SELECT, GraphQL, data caching.