Why in JPA EntityManager queries throw NoResultException but find does not?

jpa entitymanager
Jeff picture Jeff · Oct 16, 2009 · Viewed 18.7k times · Source

Can somebody tell me the intrinsic reasons why in the JPA 1.0 EntityManager when retrieving an Object via find, you have to deal with null if not found, but when using the Query interface via createQuery getResultList throws a NoResultException when not found.

Maybe i am missing something but I feel its very inconsistent for a Language, and actually I had to do a lot of redesing because of changing from a simple finder to a more fine grained query using the query interface.

Thanks guys.

Answer

Thorsten picture Thorsten · Aug 28, 2012

Queries can be used to retrieve almost anything including the value of a single column in a single row.

If getSingleResult() would return null, you could not tell whether the query did not match any row or whether the query matched a row but the selected column contains null as its value.

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