JPQL, short for Java Persistence Query Language, is a query language used in Object-Relational Mapping (ORM) frameworks, specifically Java Persistence API (JPA). It is specially designed to facilitate the retrieval and manipulation of data stored in relational databases using object-oriented concepts.
JPQL serves as an abstraction layer between the object model of an application and the relational model of a database. It allows developers to express database queries using object-oriented syntax, which is subsequently translated into appropriate SQL queries by the ORM framework.
With JPQL, developers can specify queries to retrieve entities, perform aggregation, filtering, sorting, and define relationships between entities. The syntax of JPQL resembles that of SQL, yet it operates on entity objects, attributes, and relationships rather than table names and columns.
Through JPQL, developers can easily write database-agnostic queries as it shields the underlying SQL dialect and database-specific implementation details. It empowers developers to focus on object-oriented programming concepts, allowing them to write complex queries with ease and compile-time type checking. JPQL supports a variety of query features such as joins, subqueries, functions, and aggregate expressions, enabling developers to efficiently interact with the database.
Overall, JPQL is a powerful query language that simplifies the retrieval and manipulation of data in relational databases by providing a flexible and object-oriented approach.
