Quartz Data
Quartz Data is the foundational data access layer in the Quartz Framework. It provides a lightweight, implementation-agnostic API to define and execute database operations using a consistent pattern — regardless of the underlying technology (JPA, MongoDB, in-memory, etc.).
Quartz Data does not persist data itself — instead, it defines a powerful contract for describing and querying entities that can be interpreted by various modules like quartz-data-starter-jpa.
Features
- Implementation-agnostic abstraction (JPA, MongoDB, in-memory, etc.)
- Annotation-based query definitions via @Query
- Method name-based queries (à la Spring Data)
- Support for projections, pagination, sorting, filtering
- Built-in support for custom Quartz Query Language (QQL)
Query Options
Quartz Data supports two primary ways to define queries:
1. Method Name-Based Queries
Inspired by Spring Data, you can define methods like:
Optional<Entity> findByName(String name);
List<Entity> findByScoreGreaterThan(int minScore);
boolean existsByName(String name);
long countByActiveTrue();
List<Entity> findByCreatedAtAfter(Instant time);
These are automatically parsed into dynamic queries by the framework.
2. Annotation-Based Queries
You can also write QQL queries manually with @Query:
@Query("find where score >= ?1 and active = true order by score desc")
List<Entity> findActivesWithMinScore(int score);
@Query("count where name like :pattern")
long countMatchingNamesWithParameters(@QueryParameter("pattern") String pattern);
This allows greater flexibility with projections, parameter names, and ordering.
Quartz Query Language (QQL)
QQL is a simple, expressive, and readable query language designed specifically for Quartz Data. It is ideal for basic and moderately complex queries, without requiring full SQL or JPQL syntax.
Here’s a real example using QQL:
@Query("find where score >= ?1 and active = true order by score desc")
List<Entity> findActivesWithMinScore(int score);
Next Steps
Explore the following sections to learn more about Quartz Data: