Hibernate GROUP BY对Oracle无效

Question

I created an Hibernate query like this:

select new ProjectForUser
  (p.projectId, p.name, p.description, p.client, p.startDate, p.endDate,
   p.liveDate, p.projectState, p.overallRagStatus, p.scopeRagStatus, p.flt,
   up.projectManager) 
from UserProjectAssociation up left join up.project p 
where up.user.id = :userId and up.project.projectState != 'ARCHIVED' 
group by p.projectId

to retrieve projects for user. Projects are stored in one table, users in the other and UserProjectAssociation is a joining table with additional attribute - projectManager.

The whole query works fine for H2 database, but on oracle I get this error:

ORA-00979: not a GROUP BY expression

What is a correct way to use GROUP BY for Oracle?

Thanks!

Answer 1

The Problem. ORA-00979 occurs when the GROUP BY clause does not contain all the expressions in the SELECT clause. Any SELECT expression that is not included in the GROUP function must be listed in the GROUP BY clause. These are AVG, COUNT, MAX, MIN, SUM, STDDEV, and VARIANCE.

see: https://www.tekstream.com/resources/ora-00979-not-a-group-by-expression/