What does Hibernate map a boolean datatype to when using an Oracle database by default?

As @Arthur said it maps to Number(1) which would be the standard sql bit where 0 == false and 1 == true. As an alternative you can map char(1) to 'T' or 'F' like this

@org.hibernate.annotations.Type(type="true_false")@NotNullboolean myBoolean;

or map it to 'Y' or 'N'

@org.hibernate.annotations.Type(type="yes_no")@NotNullboolean myBoolean;

Simply Number(1)

If you want, use SchemaExport to generate a script to your target database. Something like

AnnotationConfiguration configuration = new AnnotationConfiguration();configuration    .addAnnotatedClass(<TYPE_YOUR_CLASS>.class)    .setProperty(Environment.USER, <TYPE_YOUR_USER>)    .setProperty(Environment.PASS, <TYPE_YOUR_PASSWORD>)    .setProperty(Environment.URL, <TYPE_YOUR_URL>)    .setProperty(Environment.DIALECT, <TYPE_YOUR_DIALECT>)    .setProperty(Environment.DRIVER, <TYPE_YOUR_DRIVER>);SchemaExport schema = new SchemaExport(configuration);schema.setOutputFile("schema.sql");schema.create(<DO_YOU_WANT_TO_PRINT_TO_THE_CONSOLE>, <DO_YOU_WANT_TO_EXPORT_THE_SCRIPT_TO_THE_DATABASE>);

This is what you really need

Java POJO:

//@Type(type="true_false") //not working for '1' and '0' in NUMERIC(1) field@Type(type= "org.hibernate.type.NumericBooleanType")@NotNull(message="NOT_NULL")@Column(name = "IS_DELEGATION", nullable = false)private Boolean isDelegation;

Oracle DDL

alter table agent add (is_delegation number(1) default 0 not null);

As stated in Hibernate docu