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 Post subject: JPQL to SQL translation error
PostPosted: Fri Feb 11, 2011 2:33 pm 
Newbie

Joined: Fri Feb 11, 2011 2:12 pm
Posts: 2
Hi, I'm a new person here and not very familiar with neither Hibernate nor Java Persistence.

I have a very simple JPQL query with one parameter:
Code:
select e from AtomicEUP e
join e.generics g
where g.processStep = :processStep


AtomicEUP.generics is a many-to-many relationship with Generic.measurements on the opposite side. Generic.processStep is a one-to-one relationship to an entity of type ProcessStep.

For some reason the query results in the following SQL query:
Code:
select
        atomiceup0_.ID as ID8_,
        [etc...]
    from
        E_U_P atomiceup0_
    inner join
        GENERICS_MEASUREMENTS generics1_
            on atomiceup0_.ID=generics1_.MEASUREMENTS_ID_FK
    inner join
        GENERIC generic2_
            on generics1_.GENERICS_ID_FK=generic2_.ID
    where
        generic2_.ID=?


The 'join' clause seems to be correctly translated, but there is no trace of the 'where' clause. The query fails with a message "ERROR [JDBCExceptionReporter] No value specified for parameter 1".

Is there something wrong with my JPQL query statement?


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 Post subject: Re: JPQL to SQL translation error
PostPosted: Mon Feb 14, 2011 5:47 am 
Regular
Regular

Joined: Fri Jan 28, 2011 11:44 am
Posts: 117
Hi,

How do you call the execution of your query?
Given the error, it seems that you are not giving any value to the parameter :processStep ...


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 Post subject: Re: JPQL to SQL translation error
PostPosted: Wed Feb 16, 2011 6:02 am 
Newbie

Joined: Fri Feb 11, 2011 2:12 pm
Posts: 2
overmeulen wrote:
Hi,

How do you call the execution of your query?
Given the error, it seems that you are not giving any value to the parameter :processStep ...


The call was originally made like this:
Code:
Query query = createQuery(findAtomicEUPsByProcessStep);
query.setParameter("processStep", step);
return query.getResultList();


So the parameter value was set. I went around this problem by accessing the Generic object in code and using it directly in the WHERE clause and replacing the JOIN clause with a MEMBER OF expression in the WHERE clause. The query is now like this:
Code:
select e from AtomicEUP e
where :generic MEMBER OF e.generics


This produces an SQL query with a subquery in the WHERE statement, which might result in a worse performance than the JOIN statement.
Code:
    select
        atomiceup0_.ID as ID8_,
        [etc...]
    from
        E_U_P atomiceup0_
    where
        ? in (
            select
                generic2_.ID
            from
                GENERICS_MEASUREMENTS generics1_,
                GENERIC generic2_
            where
                atomiceup0_.ID=generics1_.MEASUREMENTS_ID_FK
                and generics1_.GENERICS_ID_FK=generic2_.ID
        )


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