Auto Increment A Column With Hibernate

Question

I have this situation where I need to increment a non primary key column upon insert of every new record. This column is not a primary key. However it has unique constraint. How can I use Hibernate Annotations to accomplish auto increment of this particular column? I know it can be done quite easily for primary keys, but I want exactly same thing to be done for a non primary key column (meaning without using @Id annotation?)

--Thanks

score 1 · Answer 1 · edited May 23 '17 at 10:24

1

As far as I can see, you can use the Hibernate specific annotation @Generated. Your field would look something like this:

@Generated(value="GenerationTime.INSERT")
@GenericGenerator(name="fieldGenerator", strategy="sequence")
private X field;

You can read the different types of strategies here.

I'm 90% sure that should work. If it doesn't then let me know.

edited May 23 '17 at 10:24

Community

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answered Mar 10 '14 at 07:45

JamesENL

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Would you be so kind and take a look at this: http://stackoverflow.com/questions/29976363/hibernate-generatedvalue-in-embedded-always-null maybe you can help me here. – Stefan Falk May 01 '15 at 11:27

score 1 · Answer 2 · edited Dec 06 '17 at 08:26

I checked this and Hibernate allow only one auto column (per table) and it must be defined as a key.

In addition to primary key column If you try to use more than one auto column you will get the error :

[error] o.h.t.h.SchemaUpdate - Incorrect table definition; there can be only one auto column and it must be defined as a key.

You can use sequence or table-use as sequence and save the return value as seq.

simple example of table use as sequence:

@Entity(name = "T1")

@Table(name = "t1")

public  class T1 {

    @Id
    @GeneratedValue
    @Column(name = "c_id")
    private Long seqId;

    public Long getseqId() {
        return seqId;
    }

    public void setseqId(Long sId) {
        this.seqId= sId;
    }
}

RidLam · Answer 3 · 2017-07-19T12:18:53.283

-1

@Id @GeneratedValue(strategy=GenerationType.AUTO) private int id;

it works fine for me

edited Jul 19 '17 at 12:18

answered Jul 19 '17 at 00:42

RidLam

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You are three years late in answering this question :) I have moved on to NoSQL Technologies completely. – Ace Jul 19 '17 at 19:50
`@Id` means primary key and the answer expected for non-primary-key column. – MD Ruhul Amin Dec 15 '20 at 17:11

Auto Increment A Column With Hibernate

3 Answers3