Hi,

I'm new in hibernate and have a simple question. When I don't create any keys in a db itself, just in the mapping-files of hibernate I create ids(PK) and many-to-one relations to simulate foreign keys.
Will hibernate detect in the mapping if I would make wrong inserts to a FK-property?

Thanks in advance and sorry for my bad english,
Karl

If the database doesn't enforce your FK relationships, Hibernate won't either.

Actually, that's not true. When reading an object, if hibernate can't find the <many-to-one> key in the associated table, it will throw an exception. You can define this behavior using the not-found="exception|ignore" attribute on the mapping.

So If I get you right, Hibernate works like that:

It saves an object o to table x.
After that I want to save another object ao to table y.
In the hibernate mapping of table y exists a many-to-one-relation with the first table x.
Before saving object ao to table y, hibernate will look in the database in table x if there is an object o.

Is that right???

Regards, Karl

No. Hibernate won't make sure that the o exists in table x when saving ao to table y without a FK constraint on the database. But it will throw an exception when reading the object if not-found="ignore" isn't specified on the <many-to-one>

You don't really want Hibernate to do all those extra database reads do you ? That's what database constraints are for.

You are right of course, thats the job of the database. What a stupid question I asked... With large datasets to execute a select-query every time couldn't be performant.

Thanks for your help,
Karl