Hi,

I am new to hibernate and going over Hibernate One-toMany mapping.
I have created all necessary entries and which saving i am able to save records both in parent and child table. My child is a Set.

My main problem is that while retrieving Parent, it is not populated with child values. It is showing Child as null.

Can you please suggest that where i can be wrong?

Thanks,
Gaurav

Hi,

Currently, you will be having the lazy setting as false (which is the default).
You need to either give lazy="false" in the set mapping.

or a better way would be to use the fetch join on the set entity using HQL since this would improve the performance and you could only get the columns that you want but that does involve some amount of hard coding...

Thanks a lot for your answer, but when i make lazy="false", then it started giving me below error at runtime:

could not initialize a collection

Hi,

Can you post the sample of the code?

In any case, you can try the Fetch Join using HQL.

Your query should be something like

Select a.a1, b.b1, b.b2 from a left join fetch b where <any where condition for a or b or both >

In the above query, a is supposed to have one to many mappings to b, i.e. there are many b in a.

Check the exact syntax and usage of this query.

Also, it will work even if the lazy is set to true.