We have 2 entities Technology and Project with a Many-to-Many relationship, which are linked with an additional reference table.
technologies
id name
1000 | digging
2000 | drilling
projects
id name
10 | London
20 | Madrid
technologies_projects
tech_id project_id
1000 | 10
2000 | 10
1000 | 20
I can retreive Technology from db with such a query:
@Query("select t from Technology t left join fetch t.projects")
List<Technology> findAll();
JPQL query with left join fetch clause must be used to retreive Technology with collection of projects to avoid lazy initialization exception.
The question is: How must the query be modified do get the list of technologies, used in a certain project? (the query findAllByProject(10) must return technologies 1000 and 2000).
I cannot use native SQL query here because I need join fetch to get collection of projects.
By adding a where clause on project entity.
@Query("select t from Technology t left join fetch t.projects p where p.id=10")
List<Technology> findAllByProject10();
Collected from the Internet
Please contact [email protected] to delete if infringement.
Comments