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Tag: hibernate

Deadlock when we we have dependent entities in hibernate and try to update table using multiple threads in Vertica

I have two java classes. and I receive the Deadlock X exception if several threads visit the same table (entity father) to updates with distinct row entries, even though the records are different. Is there any way to fix why the entire table locks up instead than just one row? Even though I haven’t updated or added anything

Order by 2 columns with case

I have a query that searches for user in 2 colums firstUser and secondUser and orders them by first and last name: But this first orders the cases when user is at first user then it orders the case when user is secondUser. Is ther a way to order the whole data by first name and last name no matter

Delete cascade Category child (Java Hibernate JPA)

I have this Entity to represent a Category system with a selfrelationship to get child categories: The problem is when I want to delete a category that has child categories. I want to delete all child categories but Java drops me this exception : Cannot delete or update a parent row: a foreign key constraint fails (vanger.producto, CONSTRAINT FKju4fpj8umbyi05750yjm70cx0 FOREIGN

Hibernate Table or view does not exist Oracle

I Have a problem executing an hibernate query on Oracle: my persistence.xml: my entity class com.entity.User: my java class: but when i execute my code, i obtain: Can you help me to find the error? NOTE: if a use a PreparedStatement with the same connections and query i don’t have any issue, so it is not a problem of permissions

How to create LinkedList of JPA entities

I have a scenario where I need to create an entity which has references to list of predecessors and list of successors. when a request is received, I need to create entity like below: Request: My new entity “task2” should now be created as below in DB. While saving task2 with previous as task1 and next as task3, I also

(N + 1) selects problem with child Map-collection

friends! I have these entities: Document: and ChangeNotice: And these are my repositories: For Document: and for ChangeNotice: So, when i want to get Document with changeNotices, thats not a problem, i have only one select. But when i want to get ChangeNotice with documents – i have (n + 1), first for document, and n for changeNotices Map. I