Hi,

I am using a table named vehicle in my application with a unique value licenseNo(entered by the user). I tried to use that as the primary key instead of adding another variable vehicle_id which is auto-generated. But this did not work i was having problem saving the class. I did not want to use the autogenerated id because in all my classes I will have to add an extra varibale in the class solely for that purpose.

Also when I have to search a vehicle based on a license number I have to write an HQL query instead of using load for which I wud have to know the autoassigned vehicle_id, then i have to use the setters to set the values of all other fields and there are very many fields. I was hoping I cud do it with a single load instruction.

If someone know has had a similiar problem please let me know.

Thanx in advance
Shefali

Use in your mapping:



instead

Basil

Use in your mapping:



instead

Basil

Be sure to read the documentation on using the "assigned" generator. There are several issues regarding use of this type of ID. For example, Hibernate won't be able to tell by the ID alone whether to save or update the object.

And I don't think having to use an HQL Query over load() for the License # Search is, by itself, enough of a reason not to user surrogate keys in your database. There are many papers on this subject and I would suggest reading some of them.

For example: http://www.agiledata.org/essays/dataModeling101.html

And this statement "then i have to use the setters to set the values of all other fields and there are very many fields" is incorrect. Hibernate will populate your object(s) the same whether you're using a load() or HQL query.