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springjpaspring-dataspring-data-jpa
Michal Przysucha
Michal Przysucha

Reputation: 1061

Is a Spring Data JPA @Query dynamic or named?

JPA @NamedQuery is translated to SQL only once when application is deployed and generated SQL is cached. EntityManager.createQuery translates query every time our method is called.

What Spring-data-jpa is doing with query defined in @Query annotation? Is it translated to SQL once during deployment (like NamedQuery) or translated every time (like dynamic query) ?

Upvotes: 2

Views: 826

Answers (1)

Oliver Drotbohm
Oliver Drotbohm

Reputation: 83061

Spring Data JPA calls EntityManager.createQuery(…) for every invocation of a query method annotated with @Query. The reason for that is quite simple: the Query instances returned by the EntityManager are not thread-safe and actually stateful as they contain bound parameter information.

That said, most of the JPA persistence provider perform some kind of text-based query caching anyway so that they basically build the actual SQL query once for a certain JPQL query and reuse the former on subsequent invocations.

As an interesting side note, when we started building the support for @Query in 2008 we looked into possibilities to rather register the manually declared queries as named queries with JPA. Unfortunately there wasn't - and up until today - there's no way to manually register a named query programmatically via the JPA.

Upvotes: 3

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