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Help with preventing duplicate elements in foreign key column

Ahsan Bagwan
Ranch Hand

Joined: Oct 05, 2010
Posts: 162
Using Hibernate 3.1 and have two mapping files m_devotee and m_member with classes M_devotee and M_member. I want to avoid duplicate entries from m_devotee column devotee_id which is referenced as devotee_id foreign key in m_member table.

I'm new to Hibernate and want to know if I'm missing some tags in the mappings.

Here are my files, https://gist.github.com/2e2560e7a04a769848a4

For now, I tried to prevent duplicates by adding code in my dao file. It gives me a ClassCastException. It should also rollback the transaction and return false to the servlet so it does not forward it to other jsp file.



M_devotee object cannot be cast to M_member as seen here.

I'm lost and any help is thoroughly appreciated!
surendra babu k
Greenhorn

Joined: Oct 21, 2011
Posts: 11
Hi....

before creating List you need to create a alias name for M_devote as m
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: Help with preventing duplicate elements in foreign key column