queryitem

Queryitem is a unit of a query used in database interfaces, search APIs, and query builders. It represents a single criterion or constraint that must be satisfied as part of the overall query. In typical implementations, a queryitem encodes four core elements: the target field or attribute, the operator specifying the relation (for example, equals, not equals, less than, contains, in), the value to compare against, and a logical connector or grouping flag that indicates how it combines with other items (such as AND, OR, or a grouping parentheses). Some designs also include a negation flag to express NOT conditions.

Variants and related concepts: Depending on the system, a queryitem may also be used to express a projection (the fields to return) or a sort order, though these are often modeled as separate items. In most query builders, multiple queryitems are assembled into a composite filter that the engine translates into a target query language, such as SQL, NoSQL queries, or a specialized search syntax.

Data model and validation: A queryitem is typically represented as a small data structure or object with type-safe fields. Validation logic ensures that the operator is compatible with the field type and that values are properly serialized for the target backend.

Usage: In user interfaces, users add, remove, or group queryitems to refine results. In programmatic use, developers construct collections of queryitems to programmatically build complex queries.

See also: query builder, filter, predicate, SQL, search API.