Question

I have a Project that has many Tasks.

I have a SQL query that returns all the projectIds for a userId by querying the TASKS table … here it is:

SELECT DISTINCT(projectId) 
FROM TASKS
WHERE userId = '55' AND status = 'IN_PROGRESS';

First, I’m wondering is there an easy JPA way to get all the Project objects given the list of project ids?

Second, how can I make a JPA query that does what this SQL does? I’m guessing it would have to be something like:

SELECT DISTINCT(Project p)
WHERE /*one of the tasks*/ p.tasks[].userId = '55' AND p.tasks[].status = 'IN_PROGRESS';

But I have no idea. Any suggestions are GREATLY appreciated!

Rob

Answer 1

I’m wondering is there an easy JPA way to get all the Project objects given the list of project ids

select p from Project p where p.id in :projectIds

how can I make a JPA query that does what this SQL does?

select distinct project.id 
from Task task
inner join task.project project
where task.userId = :userId and task.status = :status;

Read documentation about JPQL, because this is pretty basic stuff. Here’s the Hibernate documentation on HQL, which is a small superset of JPQL.