Hello,

Relatively new to Hibernate, I am trying to perform a query by example on Views. However, none of the restrictions I place are converted to SQL, resulting in a WHERE (1=1) irreguardless of how many parameters I set in my example object.

I have heard that Hibernate ignores ID's while performing QBE. Is there any possibility that Hibernate is seeing the whole view row as an ID, effectively ignoring any set values?

Is there anyway to get around this, besides creating a table for each view?

Thanks for any help!

Robert

Did you read the rules for this forum? They include tips on how to resolve trivial problems like this yourself.

I’m sorry but I don’t believe this is a trivial problem.

We used middlegen to generate the mapping file which created composite ids including all the fields.
Posting http://forum.hibernate.org/viewtopic.php?t=927063 states that QBE ignores IDs (not mentioned in the documentation of QBE, BTW), so we rewrote the mapping file for the view so that there is only one field as id and the rest as properties and QBE still didn’t work.

Is there anything we are overlooking, or is there any documentation you could point us towards instead of being so vague.

Thank you,

Robert

Why would you use QBE if you know the identifier value of a single instance and could use load() or get()?

The example object uses a hibernate mapping file generated by middlegen on a VIEW. Middlegen creates a composite id of ALL fields in the view, So ANY search is a search on an ID.

Is there any way for it to form a valid where statement in this case?

Yes, use load() or get() with an instance of your entity class as the primary key object.

I don't think you understand the problem. We are not looking for a single entity, we are looking for a list of objects.

And you have the primary keys of those objects, right? Use load() or get() to retrieve them.

Thanks for all your help,

We determined that the problem was with the mapping files for our views-- we had all properties set as "key - properties" (a composite id) . This caused hibernate to ignore all fields for QBE because (as we learned from searching the forum) Hibernate QBE ignores ID fields. That is why we were getting where(1=1) even when setting values on our example object. We picked a field to be the ID, and set the other fields to 'property'.

You may want to make a note of the fact QBE ignores ID fields. For simple primary keys it makes sense, but composite IDs create surprises.

Very Good Point. This for some reason never occurred to me before.

Would you please add a JIRA issue, pointing this out. I think this is a bad limitation of our QBE.

Has the QBE issue for querying on part of a composite key been addressed?

I just stumbled on this by googling my problem and in 3.3.2.ga this is still a problem. I tried to query by example an object with an id value and it refuses to add it the sql. I dunno if this is by design, but it's very annoying.

In my case, I want to test "a.b.c.id". The intuitive way to set this up is creating 3 criteria queries, one after the other and then on the 3rd example, we want to set id to the value I want.

Unfortunately, the framework just ignores it and there is no optional setting to tell hibernate not to do this.

As it stands, I guess qbe doesn't work in practice? I can't do anything else other than the ID - nothing else is unique.