HiLo generator strategy not working

Question

I am new to hibernate. What I am trying to do is use @CollectionIdto generate an identifier for my Address class. I have used Collection interface for

Answer 1

You must choose from one of the Hi/Lo strategy :

• SequenceHiLoGenerator : to back the Hi with a Sequence
• MultipleHiLoPerTableGenerator : to back the Hi with a Table

To be as close as your tutorial as possible, I would simply change "hilo" to "seqhilo" in your code.

Answer 2

Hilo is not supported anymore, this should work

@GenericGenerator(name="sequence-gen",strategy="sequence")

Answer 3

FYI, MYSQL supports sequence strategy however table name should not contain hyphen '-' (which is name provided in @GenericGenerator(name) could cause DDL exception while creating sequence table in mysql.

Answer 4

If we are using mysql it would be better to use the @GenericGenerator of increment strategy.

1. sequence - This sort of strategy supports by Oracle, Postgresql.

2. increment - This sort of strategy supports by MySql.

   @ElementCollection
   @JoinTable(name="USER_ADDRESS", joinColumns=@JoinColumn(name="USER_ID"))
   @GenericGenerator(name = "increment-gen", strategy = "increment")
   @CollectionId(columns = { @Column(name="ADDRESS_ID") }, generator = "increment-gen", type = @Type(type="long"))
   private Collection<Address> listOfAddress = new ArrayList<>();
   

When I have used the sequence strategy with MySql I came across an issue where my ADDRESS_ID is not getting incremented properly.

Answer 5

This is what works for apps on PostgreSQL. Though I have not tested it, it should work for all DBs. Note that increment-gen is used not sequence.

@ElementCollection
    @JoinTable( name = "user_address", joinColumns = @JoinColumn( name = "user_id"))
    @GenericGenerator(name="increment-gen",strategy="increment")
    @CollectionId( columns = { @Column( name ="address_id") }, generator ="increment-gen", type =@Type( type ="long"))
    private Collection<Address> listOfAddresses = new ArrayList<Address>();

Answer 6

I would recommend you to try any of the below 2 solutions and it will fix your issue. it is as per the specification provided in Hibernate 5.2.X.

Source Of Info -https://docs.jboss.org/hibernate/orm/5.2/userguide/html_single/Hibernate_User_Guide.html

Solution 1 -

 @GenericGenerator(name = "product_generator",strategy = "org.hibernate.id.enhanced.SequenceStyleGenerator")
 @CollectionId(columns = { @Column(name="ADDRESS_ID") }, generator = "product_generator", type = @Type(type="long"))*

Solution 2 -

*@GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "product_generator")
 @CollectionId(columns = { @Column(name="ADDRESS_ID") }, generator = "product_generator", type = @Type(type="long"))*

Let me know if it helps you.