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

Question

By default if I create a field in an entity like:

@NotNull
boolean myBoolean;

And I let Hibernate auto-create my tables. What Oracle data type will this map to?

Answer 1

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>);

Answer 2

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")
@NotNull
boolean myBoolean;

or map it to 'Y' or 'N'

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