Regression in 3.0 when combining 1:n relation, @EntityGraph and Pageable

[steffen-schaefer]

Hello,

We identified an issue in 3.0.0 snapshots regarding paging under the following circumstances:

• Entity A has a 1:n relation to entity B
• There are A entries having multiple B values
• Using a spring data JPA query with Pageable parameter and Page result
• An @entitygraph is added to the query which includes loading the collection of B values on A

In this case, the following happens:

• The resulting query includes a left join on B which in combination with paging returns less results than requested via Pageable
• The resulting Page's totalElements is equal to the number of values contained in the page

The described scenario works fine using 2.7.x.

A minimal reproduction scenario is attached
demo.zip

Thanks in advance!

[schauder]

I turned your demonstrator in a GitHub repository and reproduced the issue using the EntityManager directly.

I therefore conclude that this is a Hibernate regression and you'd need to file an issue with them to get it fixed.

[steffen-schaefer]

Thank you for the thorough analysis. We filed an issue in Hibernate Jira: https://hibernate.atlassian.net/browse/HHH-15880