com.googlecode.n_orm

Annotation Type Key

@Retention(value=RUNTIME)
 @Target(value=FIELD)
public @interface Key

Defines a java attribute as a key. Keys have constraint on their type as defined in documentation for Persisting. Double and float are not supported. Persisting elements must define at least one key. Non Persisting elements that have to be persisted in the store (e.g. as property value or in a column family as an index or a value) must define only keys properties. In case a class defines more than one key, those keys must be given an incrementing order(). First order is 1. Instances of such classes can be represented and rebuilt by a String using ConversionTools.convertFromString(Class, String) and ConversionTools.convertToString(Object).

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
int	order The order of the element that must differ from order of other keys.
boolean	reverted Whether the key should be stored in an inverted way ; supported types are integer (long, Long, etc), boolean, and Date.

Element Detail

order

public abstract int order

The order of the element that must differ from order of other keys.

Default:

1

reverted

public abstract boolean reverted

Whether the key should be stored in an inverted way ; supported types are integer (long, Long, etc), boolean, and Date. A search is always performed according to a start key and continues using ascending order (StorageManagement.findElements()). Inverting a key changes the order of elements.
An example is Date keys, as in the following class:
public class Foo { @Key public Date bar; }
Searching Foos like in StorageManagement.findElements().ofClass(FooStd.class).withKey("bar").greaterOrEqualsThan(d).withAtMost(100).elements().iterate() will iterate over elements whose key bar is later or equals than date d. Reverting the key, those elements would be elements earlier or equal than d.

Default:

false