Hello,

First time Hibernate user having trouble getting sequences working.

I use annotations to configure my POJOs, and here is an example of a place I specify my sequence:



I can see in my debug output that Hibernate actually does a call to this sequence, and I have had an issue where it threw an Oracle error because I initially forgot to create the sequence specified, and the error went away after I created it.



However, it seems Hibernate is not even using the sequence number it selects, because I am seeing it use numbers such as:



Those are exactly the last 4 records I inserted.

Meanwhile, if I do this:



I get the result:



So something is definitely wrong! I just dont know what it is....

What am I missing?

I specified my hibernate with following properties:



The database is setup from a JNDI datasource.

When trying to research this issue I came across some talk about a entityManager in Spring config files and I thought oh maybe I need to add that but then it started to get confusing so I need to ask do I really need to do that? In my Hibernate book it didnt mention anything like that....

I got to the point where it complained about a missing persistence.xml file and when I tried creating some from examples I am finding I'd have to repeat properties I set on Hibernate in here such as dialect and datasource so I really feel like it might be going down the wrong path.

I found a solution to my problem. I don't understand why it made such a difference, but I am at least satisfied it works.

I modified my annotation as follows:



Would like to know why this made it work "properly" instead of the default behavior working like it's supposed to. Now with those attributes added, Hibernate is taking the actual next value of thew sequence instead of some large arbitrary number and incrementing 1 by 1 instead of by 50.

i somewhere read that hibernate uses the allocationSize * current sequence value.
That results in 4296700 for your next insert, when you consider that the standard batch size is 50.

Hibernate does that so taht it does not have to select the next sequence value on every insert.
Your "fix" is the same one i used on similar problems. Reducing the allocationSize to 1 enforces hibernate to call the sequence every time.
That is fine for me, but may result in less performance during inserts...

That of course does not explain why you encounter the error whith the default value...