findByProperty

findByProperty is a common convention in data access frameworks for retrieving entities by the value of one of their properties. The pattern reduces boilerplate by allowing developers to express a query through a method name or signature rather than writing explicit query strings.

In frameworks that support derived queries from method names, such as Spring Data JPA, a repository interface may declare methods like findByEmail(String email) or findByLastName(String lastName). The framework parses the method name and generates a query that compares the named property against the supplied value. The exact behavior depends on the framework and the declared return type; typical options include a single entity, a collection of entities, or an Optional wrapper.

Property names should map to mapped attributes of the entity. Nested properties may be addressed with dot notation in some frameworks (for example, findByAddress_city). Case sensitivity and null handling are framework-dependent; many support ignore-case variants and can query for null values.

Limitations include the need for a mapped property, predictable naming conventions, and potential performance costs if overused or used on unindexed properties. Alternatives include explicit query annotations, the Criteria API, or query-by-example patterns. The generic concept of findByProperty is widely used across ORM frameworks, but exact syntax and capabilities vary.