Hi,

I am using EJB3/JPA for our application .. We have a table that has got 2 million rows..every few seconds we have to insert new records into it.Since there is no assurance that the record will not duplicate from the UI part,
we have a composite key for that too.

The problem :
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Previous developers used to check for the existence of that particular record in the DB using the composite key and if present,they will print a message in the log.Else they will persist the record using persist() method.

Since i thought it involves two hits to the DB, thought of using merge (keeping in mind that this would work similar to Hibernte's saveOrUpdate)..it abruptly failed..

Do we have anything in EJB3+JPA to just like that save the record whether it is new or old..won't the JPA detect as Hibernate does ?

If that feature is not there in EJB, isn't it limiting the powers of Hibernate, sitting on top of it ?

Any help would be appreciated.

--Venuwin

Merge is not saveOrUpdate and the only way hibernate can do saveOrUpdate is by examining id column and comparing them to their unsaved value as specified. So you probably need to set a proper unsaved value for them and you are good.



Farzad-

Hi Farzad,

Can u be specific about the approach that i need to do ?

Is there any approach available other than looking up the DB for the existence of the data and then firing a persist() if it doesn't exist in the DB.

Hmm, can you tell from the entity's primary key whether not it exists in db? If not, then you might want to look into putting a unique constraint on the keys and call insert each time. Upon a unique constraint exception then you might want to try to update it. However, I am not if this is the best way. We can wait to see if someone else has any better idea.


Farzad-