Fast Object Database for Java - with JPA/JDO support

Basic.optional - JPA annotation element

Annotation Element
javax.persistence.Basic
boolean optional

(Optional) Defines whether the value of the field or property may be null. This is a hint and is disregarded for primitive types; it may be used in schema generation. If not specified, defaults to true.
Default value:
true
Since:
JPA 1.0