DoubleJdbcType#getDdlTypeCode -> Types.FLOAT?

Hibernate ORM
1

Hi,

I have a problem with the double type conversion to DDL because the method Double JdbcType#getDdlTypeCode return Types.FLOAT.

It’s volontary? I think yes but i don’t undestrand.

Thank you.

image

My solution, override the DoubleJdbcType and DoubleJavaType :

public class EfluidDoubleJdbcType extends DoubleJdbcType {

  public static final EfluidDoubleJdbcType INSTANCE = new EfluidDoubleJdbcType();

  @Override
  public int getDdlTypeCode() {
    return Types.DOUBLE;
  }
}

public class EfluidDoubleJavaType extends DoubleJavaType {

  public static final EfluidDoubleJavaType INSTANCE = new EfluidDoubleJavaType();

  @Override
  public JdbcType getRecommendedJdbcType(JdbcTypeIndicators indicators) {
    return EfluidDoubleJdbcType.INSTANCE;
  }
}

public class EfluidTypeContributor implements TypeContributor {

  @Override
  public void contribute(TypeContributions typeContributions, ServiceRegistry serviceRegistry) {
    typeContributions.contributeJavaType(EfluidDoubleJavaType.INSTANCE);
    typeContributions.contributeJdbcType(EfluidDoubleJdbcType.INSTANCE);
  }
}
2

Since you don’t explain what the problem is that you have I can’t really help you. The way this is designed is on purpose.

3

Yes sorry.

My problem is i must get the format in database of a column for generate the DDL
And the java type double are number type and not float int the BDD.

It is a comparison that is expected :

image
image1112×138 23.9 KB 

public class MappingSQLType {

  public static String getSqlType(Column columnHibernate) {
    if (columnHibernate.getValue() instanceof SimpleValue value) {
      return columnHibernate.getSqlType(value.getMetadata());
    }
    return null;
  }
}
4

Well, if you want to map your Double fields in the database as number DDL type, then I would recommend you to do that on a per-field basis with @Column(columnDefinition). If you have many columns and want all of them to use the same mapping, you can register that in the DdlTypeRegisty, by calling addDescriptor( new DdlTypeImpl( SqlTypes.FLOAT, "number", dialect ) ) within e.g. a custom org.hibernate.boot.model.TypeContributor

1 Like
5

It’s a good idea, i will test that. Thank you !

6

It’s ok ! :smiley:
Thanks.

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7

The implementation:

public class EfluidTypeContributor implements TypeContributor {

  @Override
  public void contribute(TypeContributions typeContributions, ServiceRegistry serviceRegistry) {
    typeContributions.contributeJavaType(ListEnumTypeJava.INSTANCE);
    Dialect dialect = serviceRegistry.getService(JdbcEnvironment.class).getDialect();
    typeContributions.getTypeConfiguration().getDdlTypeRegistry().addDescriptor(new DdlTypeImpl(SqlTypes.FLOAT, "number", dialect ));
  }
}
8

Can you explain why you need a ListEnumTypeJava? Hibernate 6.2 properly supports stuff like @Basic List<MyEnum> already and maps that to e.g. tinyint array or smallint array on the DB if possible, and falls back to varbinary if the DB does not support arrays natively.

9

Sorry, it’s a enum custom from us framework, not the java enum.

public class ListEnum<T extends EnumerationType> implements Serializable, Cloneable, Iterable<T> {
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